Using USB Temperature Dataloggers

Exploring the microclimate of a school

The investigation of small-scale climates around schools and field centres has long been a popular project. USB temperature loggers make this project very easy to undertake with a high probability of success. Microclimates are most pronounced at night, especially on clear nights when an open area can cool several degrees below a more sheltered courtyard, for example. But using pupils to measure night-time temperatures is impossible at most schools; loggers can be left out for several days and do this easily.

usb temperature datalogger
The USB temperature logger
temperature datalogger in pot
Protected by a yogurt pot and pinned down

The Mindsets USB temperature logger looks like a USB memory stick, but actually contains a temperature sensor, a clock and a data logger.  It can store over 8000 measurements of temperature, enabling it to sample every 5 minutes for 27 days. When plugged into a PC, the data is immediately displayed as a graph. Inserting two or more loggers in succession allows the data from all of them to be plotted on the same graph in different colours with a key.

temperature graph
Graph produced by the Mindsets software when five loggers at different locations are downloaded

How to carry out the microclimate investigation

  1. To read the USB logger you will need to download the programme on to your PC. Google the following: Mindsets 161-357 which takes you to the website for the product, click on the Downloads tab at the bottom and then on Mini Datalogger Software. Follow the instructions to install – it is very quick.
  2. Before using the loggers in the field, it is worth familiarising yourself with how to use them; most of it is pretty intuitive, but worth a quick run through here. Open the Mindsets programme on the PC and plug one of the loggers into a USB port. Click on Add data and enter the number of the logger when it prompts you for a Name, then hit OK. A labelled plot of the temperature history of the last 28 days (including when it was in transit to you) will appear. Remove and repeat with another logger, which will show a second plot – which will be similar because they have been transported together, of course.
  3. Delete this old data from each of the loggers in turn to avoid it confusing the analysis of data you are about to collect – see Note 3 at the end.
  4. Take each USB logger and put it in a small yogurt pot (supplied in the kit), press down the lid tightly to exclude rain and dew, and label the pot with the number of the logger.
  5. Next, choose a number of locations around the school which have different amounts of shelter. The most open might be the middle of a sports field; the most enclosed might be a non-roofed central courtyard, for example. In between these, in terms of shelter, might be under a large tree, on a tennis court, on a flower border next to a wall, etc.
  6. Take the loggers to the chosen locations, make a note of which one goes where, and also label each pot with the location (e.g. “under tree”). At each location, pin them down securely with a couple of wire hoops (made from a coat hanger – one is supplied in the kit as an example); this will stop animals walking off with them. If there is no soil to pin them down into, put wire round the pot and pin the wire down with a brick. It is worth telling other people in the school (e.g. groundsman) so that they don’t just pick them up as litter.
  7. After number of days, ideally when there has been at least one good clear night, bring back the loggers. As before, open the Mindsets programme on the PC and plug the first logger into the USB port. Click on Add data and enter the location of the logger when prompted for a Name, then hit OK; a labelled graph of the temperature history will appear. Remove and repeat with the other loggers, until you have built up a graph with several different coloured labelled plots – see example above. Click on File at the top LH corner, then on Save plot as Image and give the plot a meaningful name, e.g. Temps up to 02 Apr 2014 (if you want, you can also save the temperature data for use later in an Excel spreadsheet by going to File and then Export data to CSV file)
  8. Look in the temperature plot for the night when temperatures are lowest – this will almost certainly be a clear night – and read off the minimum temperatures for each of the locations. Plot the temperatures on a plan or Google Earth photo of the school – see the example below.
  9. Look for a warm night on the graph – this will almost certainly be a cloudy night. Read off the minimum temperatures on this night. Again, plot them on a Google Earth photo of the school.
  10. Discuss the reasons why minimum temperatures are different at different locations and different on cloudy and clear nights. See the page on “What can we learn?”  
temperature graph
The same graph as above, annotated to show some important features of the temperature record.
school microclimate
Minimum temperatures around a school on the night of 22/23 Dec 2013, read off from the graph above. This shows over 8⁰C difference between an open but roofed area and the rugby pitch, with other temperatures in between.

What can we learn from the observations?

When the sun shines, it warms up the ground, which in turn warms the air around us, which is why it is warmer by day than by night. But all the time, heat (in the form of invisible infra-red radiation) is being given off by the surface of the ground, and this cools the surface, and hence the air. At night, when there is no sun to warm us, temperatures will fall throughout the night and reach a minimum in the early morning.

The amount of heat given off by the ground will depend on its location. Open ground will radiate to the sky everywhere, so lots of heat will be lost, and the temperature will fall.  At a well sheltered location, for example in a courtyard, much of the heat that escapes from the ground “bounces back” off the walls of the courtyard, so the cooling will be much less rapid. In between these two extremes, for example at the base of a wall which is open to only half the sky, temperatures will fall less rapidly than in the open, but less than when completely enclosed.

If the night is clear, the heat emitted from the ground can escape freely to outer space, so open ground will cool down rapidly. There will be a big difference between the temperature measured by a logger left out in the open, compared to one in a more sheltered location.

If the night is cloudy, much of the heat emitted by the ground will be reflected back by the clouds, so the temperature will not fall as much.  So on a cloudy night, differences between the very open site and the very sheltered one will be much less, because clouds are sheltering all the locations.

microclimate building
On a clear night in an open area (left) heat (in the form of infra-red radiation) from the ground can radiate out to the whole sky, so the ground will cool rapidly. But at a location next to a wall (right), the wall reflects half the heat back and stops it from being radiated to the sky, so the ground will cool less rapidly.


  1. Of course, the loggers continue to measure during the day as well as the night, but when sunshine falls on them it heats them up to above the air temperature, so the data will be in error. Some loggers in the graph above show spikes on 22 Dec 2013 where sun has affected the reading. The simplest thing to do is to just ignore all readings between sunrise and sunset – we only need data when it is dark.
  2. There is probably less chance of the loggers being interfered with if this investigation is done over the weekend, i.e. leaving loggers out on a Friday afternoon, and retrieving them first thing Monday morning.
  3. Having old data in the loggers will make plotting an analysing new data much more difficult, so erase the old data from each logger. Again, it’s pretty intuitive. Plug one in and click on the Erase data button to get rid of the old data. Then click on the Configure button, which gives the popup shown below, and set the loggers to sample every 5 minutes and click OK. Also click on OK in the next popup that says Changing setting will erase data. Do not alter anything in the other boxes. Repeat with the other loggers.
temperature datalogger

Top 10 Ideas for Weather Fieldwork

Here are some ideas for simple, fun weather related fieldwork which you can try out in the school grounds. We started off with 10, but then had more!

Bubble chase – see which way bubbles drift in the wind to determine the wind direction and speed. Here is some guidance.Bubble chase

Does rain always come from dark clouds? Use our colour chart to find out. Or, use a home made cyanometer to see how blue the sky is, and link it to art or to discussions about why the sky is blue, and how pollution affects it.

 – how long does it take an ice cube to melt in different places?

Identifying cloud types. You could use our Metlink Bookmark, cloud wheel or cloud chart.clouds

Which way are the clouds moving? You can use the OPAL guide to making a nephoscope for this.

Wind speed – use the Beaufort Scale to estimate the wind speed.

Cloudiness – you could either record as ‘Clear sky, mostly clear, mostly cloudy or overcast’, or record in oktas, using a cloud mirror (using a ruler, draw a grid of lines onto a square mirror so that you have 16 equal size boxes; look at the sky with the mirror. How many boxes are mostly cloudy? Divide by 2 to give oktas and repeat for different bits of the sky to get an average).cloud mirror

Evaporation – draw around the edge of a puddle to see how long it takes to evaporate (guidance here).

make your own rain gaugeRainfall – make your own raingauge using our DIY sheet. If you can, use paraffin wax (sold by candle making suppliers) rather than jelly.

frost patternsCollecting and looking at snowflakes with a hand lens or tracing frost patterns on car windows.

raindrops in flourRaindrop size measuring using a sand tray or blotting paper. There is a fairly high level guide here but it could easily be adapted for all levels.

Where is the warmest/ coldest spot in the school? Or, if you want to take wind speed into account too, Where would you put a picnic bench?

WOWWhat’s the temperature in your school grounds today and somewhere else in the world/ UK?A very good way of seeing this is to use WOW. By zooming in and out, you can compare temperatures locally and around the world.

Record temperatures for a week in your area and in another city elsewhere? Can you compare them?

contrailsContrails (OPAL) – Use this guide to record what sort of contrails you can see.

Fieldwork in Geography

Fieldwork support documents:

Our top ten ideas for weather fieldwork.

Infrared Thermometers: worksheet with ideas for use with KS2 and above science and geography students.

USB temperature dataloggers. Guidance document and report from Weather magazine.

Urban wind flow: a PowerPoint presentation introducing how the wind is affected by urban structures and notes for teachers introducing simple fieldwork which can be carried out in the school grounds, using bubbles.

Urban Heat Islands: a three lesson geography resource aimed at KS3 or higher, using a class set of simple digital thermometers to make a temperature map of the school’s catchment area. The lessons cover Urban Heat Island background information, fieldwork planning and data collection, display and analysis. Teachers notes and PowerPoints 1, 2 and 3.

School microclimate: a two lesson geography resource aimed at KS2 using an anemometer and digital thermometer. Students gather information about the wind and temperature in the school grounds, then use PhotoStory to present their results. Teachers notes and introductory PowerPoint.

Instructions to make your own instruments on our Experiments and Demonstrations page.

More ideas on our Observations and data page.

Find out how you can borrow weather instruments from the Royal Meteorological Society free of charge.

Fieldwork in A Level Geography

Further information about making weather measurements in A Level geography

Find out how you can borrow weather instruments from the Royal Meteorological Society free of charge.

Using Kestrel Weather Stations

A Kestrel Weather Station

For Independent Investigations / A Level Non-Examined Assessment (NEA)
Weather data can be used for lots of interesting investigations and is also a useful addition to many investigations – the weather can affect both physical processes and human ones. Are the responses people give to surveys affected by the weather? How does this extend to other forms of behaviour – how people travel, what activities they choose to do? What impact do microclimates have on land use – and vice versa? Weather data can be obtained directly (primary sources) using instruments – which may be simple (homemade or cheaply available) or highly precise, professional instruments. You can find guidance about how to make accurate weather measurements in this document, which is also available as a short video. Note that much of the guidance about how to use a thermometer etc. appropriately is applicable to a Kestrel weather station.
This guidance forms part of the wider Royal Geographical Society’s student guide to the A level independent investigation (NEA) where you can also find some more detailed ideas forweather and climate fieldwork.
The Royal Meteorological Society has also produced quick guides to using Kestrels Kestrel 4500 guide Kestrel 5500 guide and some other useful links and ideas for weather fieldwork and investigations.
You can borrow Kestrel weather stations from the Royal Meteorological Society for your NEA/ Independent investigation. This scheme is supported by Richard Paul Russell.
For Expeditions
Royal Meteorological Society Kestrel weather stations have accompanied expeditions to places as far afield as Madagascar, India and Norway. You can read some of the trip reports here, here and here.
You can borrow Kestrel weather stations from the Royal Meteorological Society for your expedition – it doesn’t need to be to an exotic location, but you do need to have a clear scientific purpose for your trip.
If on the other hand you would like to purchase your own instruments, Richard Paul Russell are offering a 10% discount off all products with the code RMETS2019.Richard Paul Russell logo

Kestrel Weather Station
Kestrel in Ladakh

Borrow an Instrument

Schools, teachers and Society members in the UK can borrow instruments such as anemometers, thermometers, rain gauges, infrared thermometers and Kestrel weather stations from the Society.

We are also able to lend Kestrel weather stations to students carrying out independent investigations at A Level.

We are very grateful to PCE instruments and Richard Paul Russell for supporting our instrument loan scheme.

UK schools may apply to the Society for the loan of instrument packs, which include lesson resources and the instruments needed to do the fieldwork, for a period of half a term. Please contact the Head of Education at to arrange to borrow a pack. This scheme is extremely popular and we recommend requesting a pack at least 2 terms in advance to avoid disappointment.

We simply ask borrowers to cover the postage and packaging costs (approximately £13) for returning the instruments and to take responsibility for any accidents or loss whilst the instruments are on loan to you.

We also have a list of suggested investigations which can be carried out with the loaned equipment.

The contents of the instrument packs are something like:

Key Stage 2 Pack

10 Infrared thermometers

1 digital anemometer

1 raingauge

2 USB temperature dataloggers

Key Stage 3/ 4 Pack

10 Infrared thermometers

2 digital anemometers

5 USB temperature dataloggers

A level

We have some Kestrel hand-held weather stations, with tripods, wind vanes and USB download ports available to A level students and school expeditions. Please contact the Society at to discuss availability.

“I wanted to say personally what a huge difference the kit has made to the Advanced Higher students. It enabled some of the students to focus on their real area of geographical interest when they were thinking they would have to compromise and allowed me as the teacher to give real context to the gathering techniques that we needed them to know for their coursework and exam. It really has been invaluable and I can’t thank you enough for the fantastic service you are providing schools”.

Find out more about using weather measurements in an A Level Independent Investigation or other fieldwork. Our instruments frequently accompany school expeditions to amazing locations.

Kestrel weather station
Kestrel in Ladakh

Beaufort Scale

Beaufort wind scale for land areas

  • Make your observations in an open location, e.g. school field.
  • Use the scale below to estimate wind speed.
  • Enter CALM if there is no wind.
Wind Force
0Calm00Smoke rises vertically
1Light Air1-51-3Direction shown by smoke drift but not by wind vanes
2Light Breeze6-114-6Wind felt on face; leaves rustle; wind vane moved by wind
3Gentle Breeze12-197-10Leaves and small twigs in constant motion; light flags extended
4Moderate Breeze20-2811-16Raises dust and loose paper; small branches moved.
5Fresh Breeze29-3817-21Small trees in leaf begin to sway; crested wavelets form on inland waters.
6Strong Breeze38-4922-27Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.
7Near Gale50-6128-33Whole trees in motion; inconvenience felt when walking against the wind.
8Gale62-7434-40Twigs break off trees; generally impedes progress.
9Strong Gale75-8841-47Slight structural damage (chimney pots and slates removed).
10Storm89-10248-55Seldom experienced inland; trees uprooted; considerable structural damage
11Violent Storm103-11756-63Very rarely experienced; accompanied by widespread damage.
12Hurricane118 plus64 plusDevastation