Images depicting the weather...
Ruining everyone's fun
Ruining the mood
Making people sick
Being inconsistent, like raining one moment, and then stopping the next.
Pretty much whenever weather is being the main source of annoyance or greatly making it worse.
Different kinds of weather may include rain, hail, snow, heat (such as a heat wave), freezing temperatures, wind, storms, and anything else that you believe falls under weather.