Have You Had Your Hottest Day Of The Year Yet?

If you've had enough of summer's stifling heat and are ready for it to ease, then you might be wondering if the hottest time of year has passed.

We have the answer key below, which shows when the average hottest day of the year happens based on the 1991-2020 average from NOAA.

Big Picture

• A Common Peak Time: It's probably no surprise, but July or early August is when average peak of summertime heat arrives for most Americans, as shaded in the various orange colors.
• Why Peak Happens After The June Solstice For Most: The sun is highest in the sky and delivers its most direct radiation over the Northern Hemisphere at the summer solstice. But it actually takes weeks to warm up Earth's surface enough for appreciable changes. It then takes more time for the air above the land to warm. So that's why there's a seasonal lag between the solstice and the typical hottest day of the year.
• Peak Can Deviate From Long-Term Average: In any given year, bulging heat domes of high pressure aloft can deliver the year's hottest weather for a few weeks on either side of these average dates. For example, the Northeast saw a record-smashing heat wave in late-June 2025, which is well ahead of its mid-to-late July long-term average peak.

Deeper Dive Into The Details

• Earliest Peak Is In Desert Southwest: The hottest time of year in both El Paso, Texas, and Tucson, Arizona, is usually in the last week of June. In Phoenix, it's in early July. This is generally before the North American monsoon kicks into a higher gear by sometime in July and August. The increased moisture and resulting showers and storms can keep temperatures from rising as high at times in those months when compared to June.
• July Is The Heat Champion For Most: July is when the average hottest day of the year happens in a large area that stretches from the central Rockies to the Central Plains, upper Midwest, Great Lakes, Ohio Valley and East. The hottest time of year is usually in mid-July in New York, Washington, D.C., and Chicago, and in late July in Atlanta, Denver and Kansas City.
• August For The South-Central States: Early August tends to be the hottest time for parts of the South from central and eastern Texas into the Ozarks and lower Mississippi Valley. That includes Austin, Dallas, Houston, Little Rock and New Orleans. In South Texas, the hottest time of year skews toward the middle of August. By that time, the somewhat daily slow-moving thunderstorms of early summer give way to more persistent high pressure over the South that suppresses clouds and dries soil, helping temperatures to soar.
• West Coast Lag: In the heart of summer, onshore winds keep low clouds, fog and cool air firmly in place along the coast. Beginning in September, the upper-level wind pattern can set up to drive hot, dry winds from the interior to the coast and offshore, known as Santa Ana winds in Southern California and Diablo winds in the Bay Area. Because of that, downtown San Francisco's hottest time of year is near the end of September into early October. In downtown Los Angeles, however, the seasonal heat peak is earlier, generally in late August, though they can certainly see a heat spike in a strong fall Santa Ana wind event.

• What About Alaska And Hawaii? July is generally the warmest time of the year for much of Alaska, but along the southern coastal areas, peak warmth doesn't occur until the last week of July into early August. In Hawaii, most areas don't see their warmest time of the year until August or September. Some high-mountain locations see peak summer temperatures much earlier. That said, the joy of Hawaiian weather is the relatively little change in temperature year-round in the tropical Pacific. For example, Honolulu's "coolest" average high temperature in January is about 80 degrees. Their "hottest" average high in late August is about 89 degrees.

Chris Dolce has been a senior digital meteorologist with weather.com for 15 years after beginning his career with The Weather Channel in the early 2000s.

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