Every State's Hottest June on Record, Ranked

All 50 States Ranked by Hottest June Temperature

Temperatures from NOAA GHCN-D archive. Airport and Weather Service stations (USW) prioritized for data reliability. Records validated against NOAA State Climate Extremes Committee official ceilings.

Rows highlighted: red = 2012 heat wave, orange = 2021 PNW heat dome, amber = June 2025 NE heat wave. Data from NOAA GHCN-D archive, queried June 19, 2026.

The 2012 Heat Wave: One Week, 21 State Records

Look at the table above and a pattern jumps out: 21 of 50 states set their hottest June day between June 25 and June 30, 2012. That's not a coincidence — it was one of the most intense heat waves in American history. A massive ridge of high pressure stalled over the central and eastern US, pushing afternoon temperatures above 100°F from Kansas to South Carolina for five consecutive days.

What made 2012's June heat wave different from typical summer heat: it came with severe drought. The US Drought Monitor showed 56% of the contiguous US in drought that June — dry soils amplify heat because there's no evaporative cooling. Nashville hit 109°F. St. Louis reached 109°F. Bowling Green, Kentucky hit 109.9°F. These aren't desert towns — they're humid southeastern cities where triple-digit heat with high humidity creates genuinely dangerous conditions.

The 2021 Heat Dome: When the Pacific Northwest Hit 118°F

On June 28–29, 2021, Oregon and Washington both recorded 118°F — temperatures that would be extreme in Arizona, let alone the Pacific Northwest. Portland reached 116°F, shattering its previous all-time record of 107°F by nine degrees. Seattle hit 108°F. Lytton, British Columbia, recorded 121.3°F before the town literally burned to the ground the next day.

The heat dome killed an estimated 800+ people across the region. 5 states set their all-time June records during the event: Oregon, Washington, Idaho, Wyoming, and New Jersey (which caught the tail end of a related heat wave on June 30). The event was so far outside historical norms that climate scientists called it “virtually impossible without climate change” — a phrase from the World Weather Attribution study.

When June Records Were Set: The Decade Breakdown

The concentration of records in recent decades isn't a measurement bias — NOAA has maintained reliable weather stations since the 1940s. June is genuinely producing hotter peak temperatures than it did 50 years ago.

The 2010s alone account for 26 of 50 records — more than all other decades combined. The 2020s already have 11 with four and a half years still to go. Zero states hold June records from the Dust Bowl era (1930s), which dominates July and August record lists. That tells you something about how June heat patterns have shifted.

How June Is Warming: City-Level Trends

Average June daily highs at major airport stations, by decade. The warming isn't uniform — some cities are heating much faster than others.

Seattle's 4.2°F increase is the standout — June days that averaged 68.5°F in the 1970s now average 72.7°F. That doesn't sound dramatic until you consider what happens at the tails of the distribution. A 4°F shift in the average pushes formerly rare 100°F+ days into the realm of the possible — exactly what happened during the 2021 heat dome. Atlanta's 3.6°F increase means more days above 90°F, which matters for a city where summer warming has accelerated since the 1990s.

June 2025 and the New Northeast Heat Pattern

6 states set their hottest June day last year, all on the same date: June 24, 2025. New York, New Hampshire, Massachusetts, Delaware, Connecticut, and Maine all recorded their highest June temperatures at major airports. JFK hit 102°F. Boston hit 102°F. Manchester, NH hit 102°F.

What's notable: these are the kinds of temperatures that used to be associated exclusively with the Midwest and South. When 6 northeastern states simultaneously break June records, it signals a northward expansion of extreme June heat that the broader warming data supports.

What the Data Reveals That Other Lists Miss

Frequently Asked Questions

Data Sources & Methodology

June monthly temperature records queried from the NOAA GHCN-Daily archive (139M observations across US weather stations). Airport and Weather Service stations (USW prefix) were prioritized for data reliability. Readings were validated against the NOAA State Climate Extremes Committee official all-time records. City decade averages computed from the same archive. 2021 heat dome death toll from WHO and regional health authority estimates. 1980 heat wave death toll from NOAA historical records. Query run June 19, 2026.

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