Kids commonly have confusion and misconceptions regarding the distinction between weather and climate. The distinction may need to be clarified at the outset. The following site may help in this regard:
https://oceanservice.noaa.gov/facts/weather_climate.html
Weather measuring equipment
Kids may wish to embark on monitoring and recording the day-to-day weather of their location over a period of time. Two key parameters are the rainfall (precipitation) and high and low temperatures for each day. Basic instruments they will need are a rain-gauge:
https://www.amazon.com/Rain-Gauges/b?ie=UTF8&node=397437011
and a max-min thermometer, one that gives you the highest and lowest temperature that has occurred since the last reading, as well as the current temperature.
https://www.amazon.com/s/?ie=UTF8&keywords=min%2Fmax+thermometer&tag=googhydr-20&index=aps&hvadid=174245143091&hvpos=1t1&hvnetw=g&hvrand=11168963378704105538&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007919&hvtargid=aud-344389568820:kwd-1193515688&ref=pd_sl_78nbndpi0g_e