San Francisco is seeing the coldest start to a summer in over two decades, and nobody has felt the chill more than the people tasked with painting the Golden Gate Bridge.

Fred Mixon, the paint superintendent for the bridge, said his team has used heaters on most days this summer to warm up the steel before applying the International Orange paint that defines the bridge’s iconic vermilion hue. When the steel is cold, the paint doesn’t adhere as well and can flake off after it dries.

“This is the first time in a long time that we’ve used the heaters in summer,” he said. “We are using them most days this summer, whereas in prior summers we might use them for a day or two all season.”

San Francisco, where 70 can be considered a hot summer day, is known for its cool summers, but this year, June and July were even chillier than normal. The average afternoon high downtown was 63.7 degrees, 2.7 degrees below normal, making it the coldest since 1999.

Because of the city’s proximity to the Pacific Ocean and the blanket of fog that often hugs the California coast, temperatures tend to stay cool there, even as inland areas roast in the hot sun and triple-digit heat. This summer, that nip in the air has been felt up and down the coastline of Northern and Central California and into the Sacramento Valley.

Just an hour south of the city, San Jose saw its 10th coolest start to summer, with records going back more than 100 years. The average high was 76.9, compared to the normal 81.2.