Rivalry sprang up between departments as they rushed to register complaints on the staffroom forum of the TES website.
"The art department have taken themselves outside again, and are calmly drawing in the sunshine - right outside my door. Grrr!," wrote Puffin.
"Think I may have to conduct an 'environmental survey' of the number of daisies on the school field next lesson." And it was not only teachers getting cranky, according to Vuff67.
"I wish the senior leadership at my kids' school would take a lighter view on uniform in this lovely weather. They are expected to wear their sweatshirts between lessons and get threatened with detention if they don't. If they do want to take their sweatshirt off, they have to ask permission. These kids are seriously cranky - are we surprised?"
For one contributor, though, the temperature was just perfect. "I work in a lab, so I am not allowed to let the pupils have a drink," wrote Marshypops.
"And with Bunsen burners on too, the place can be unbearable for the kids - I find the heat lovely."
For pupils at one North Yorkshire primary, the final arrival of summer spelled a day off school as flash floods left the school's two teachers stranded in their villages.
Christine Windwood, head of St Hilda's Ampleforth, York, was trapped in the market town of Helmsley after the Rye burst its banks and damaged bridges over the river on Sunday.
Lucy Richardson, the infant teacher at the 31-pupil school, was in an identical position in the nearby village of Nunnington. A month's rain fell on the North York Moors in under three hours.
On Wednesday, children across North Yorkshire raised money for a Sri Lankan school destroyed in the Boxing Day Tsunami. St Hilda's had a non-uniform day. "It was quite poignant because the children have now seen at first-hand the damage water can do," Mrs Windwood said.