Weathercatch: The year’s hottest month? Get ready to sweat

It won’t be long before summer’s heat digs in its heels. July is typically the hottest month of the year in the Inland Northwest and many other regions in the U.S.

With the June 2020 solstice several weeks behind us, you might be wondering why summer’s peak heat arrives in July. After all, the sun delivers more direct heat and longer days of solar radiation in June. This delay, called a seasonal lag, occurs because the earth’s land and bodies of water need another month or so to warm up from the cold of winter.

Chances are, if you recently took a plunge in the Spokane River or a sizable lake you felt lingering coldness. As we head deeper into July and encounter the season’s first stretch of sizzling heat, water temperatures may still be on the cool side. Even with abundant sunlight and heat, it takes more time to warm large bodies of water than it does land.

Spokanites must have flocked to area waters during what felt like an inferno on July 26, 1928, when temperatures soared to a blistering 108, the hottest temperature recorded in Spokane. The warmest month of July occurred in 1906 for both Spokane and Washington state, when temperatures ran more than 5 degrees above average for that period.

The month typically runs 6.7 degrees warmer than June and 1.2 degrees warmer than August. But there have been exceptions.

In June 2015, a strong ridge of high pressure spawned an abnormally early heat wave in the Pacific Northwest, setting dozens of record-high temperatures. Multiple days of extreme heat made July look pale by comparison. By contrast, July 1993 was a big chill for the region, with temperatures in Spokane running a hefty 10 degrees below normal for the month. The city also got 2.08 inches of rainfall, compared to the average amount of just .54 of an inch.

Similar cool, damp conditions probably won’t define July 2020. Although we haven’t broken the 90-degree mark yet, several weeks of the month await us. In all likelihood, summertime heat will soon unpack its bags and stay for a bit.