The brighter light the greater transpiration rate. stomata closes when dark. photosynthesis can’t happen in dark so don’t need to be open to let CO2 in
Temperature
The warmer the faster it happens. when warm water particles have more energy to evaporate and diffuse out stomata
Air flow
The better air flow around a leaf better rate. if air flow poor water vapour surrounds leaf means high concentration so bad diffusion rate
Humidity
Drier air the faster rate. humid lots of Water so not different concentration
