Tongue in cheek.
There shall be a huge heatwave the last week of school when the kids are too hot to do anything then without fail rain on the 1st day of holidayd followed by a cold spell. Intermittent bad weather for 6 weeks for all those taking a staycation.
The road works start the 1st week of school holidays...great for school run mums; shit for commuters.
Wasps and seagulls will congregate on the beach.
Please add to the list.