What is the hottest day ever recorded in St. Louis?

St. Louis's hottest day on record reached 115°F, set on July 14, 1954. That is the single most extreme high in the nearest long-term weather station's full daily record — about 48°F hotter than a typical year's average high of 67°F, which is why a day like it stands out as genuinely rare rather than just a hot afternoon.

What is the record high temperature in St. Louis?

The all-time record high in St. Louis is 115°F, recorded on July 14, 1954. Records are drawn from the nearest long-term weather station's full daily history, so this is the hottest single day the station has ever logged — not a typical summer peak.

What is the coldest day ever recorded in St. Louis?

St. Louis's coldest day on record bottomed out at -18°F, set on January 20, 1985. Like the record high, it comes from the station's full daily record, so it captures the most extreme cold the area has recorded rather than an average winter low.

What is the record low temperature in St. Louis?

The all-time record low in St. Louis is -18°F, recorded on January 20, 1985. The gap between that and the 115°F record high — a span of 133°F — is the full range of temperatures St. Louis has experienced across its long-term daily record.

Is it normal to be this hot in St. Louis?

It depends on how far above St. Louis's normal a given day runs. A typical year here averages a daily high near 67°F; the all-time record of 115°F (set 1954) sits about 48°F above that. When a live reading is available, the live readout just below the record high and low compares it with the temperature typical for that hour this month (estimated from the month's normal high and low), so you can see how unusual the day is rather than guessing.

When did St. Louis set its temperature records?

St. Louis's record high of 115°F was set in 1954 (July 14, 1954), and its record low of -18°F in 1985 (January 20, 1985). Both are pulled from the station's full daily record going back to 1938, so they reflect the true extremes rather than a recent or partial sample.

Has St. Louis been getting hotter?

Yes — St. Louis's annual mean temperature has trended about 3.5°F warmer since 1939 (+0.40°F per decade, fitted to the complete years of 1939–2025). That gradual shift in the average is separate from the all-time records above, which mark the single most extreme days rather than the trend, but a warming baseline is part of why recent years more often brush up against the record-high end.

St. Louis, Missouri Weather Records

The hottest and coldest days St. Louis has ever recorded — and how today compares to normal

St. Louis’s all-time temperature records

Hottest day on record: 115°Fset July 14, 1954
Coldest day on record: -18°Fset January 20, 1985

That is a 133°F span between the hottest and coldest days St. Louis has ever recorded — the full range of what its weather has done across the station’s record back to 1938.

St. Louis, MO · Today vs. normal

6°F above typical for 9:15 AM on Sep 21

At 9:15 AM CDT on Sep 21 it was 70°F in St. Louis — 6° above the 64°F typical for that hour (estimated from the Sep 21 normal high of 79°F and low of 59°F, interpolated from the monthly normals).

How extreme St. Louis’s weather gets

St. Louis’s weather is usually mild by its own standards — a typical year averages a daily high near 67°F, and the normal high for September runs about 81°F. The records sit well outside that everyday range. The hottest day on record reached 115°F in 1954 — roughly 48°F above a typical year’s average high, the kind of gap that turns an ordinary summer into a genuine heat event.

At the other end, St. Louis has bottomed out at -18°F (1985). Those edges are why the today-versus-normal readout above is worth a glance: it shows where today falls between the normal and the record, so a hot afternoon can be judged against the real history rather than a hunch. A reading a few degrees over the September normal is ordinary; one pushing toward the 115°F record is the rare event the record marks.

Frequently asked

What is the hottest day ever recorded in St. Louis?: St. Louis's hottest day on record reached 115°F, set on July 14, 1954. That is the single most extreme high in the nearest long-term weather station's full daily record — about 48°F hotter than a typical year's average high of 67°F, which is why a day like it stands out as genuinely rare rather than just a hot afternoon.
What is the record high temperature in St. Louis?: The all-time record high in St. Louis is 115°F, recorded on July 14, 1954. Records are drawn from the nearest long-term weather station's full daily history, so this is the hottest single day the station has ever logged — not a typical summer peak.
What is the coldest day ever recorded in St. Louis?: St. Louis's coldest day on record bottomed out at -18°F, set on January 20, 1985. Like the record high, it comes from the station's full daily record, so it captures the most extreme cold the area has recorded rather than an average winter low.
What is the record low temperature in St. Louis?: The all-time record low in St. Louis is -18°F, recorded on January 20, 1985. The gap between that and the 115°F record high — a span of 133°F — is the full range of temperatures St. Louis has experienced across its long-term daily record.
Is it normal to be this hot in St. Louis?: It depends on how far above St. Louis's normal a given day runs. A typical year here averages a daily high near 67°F; the all-time record of 115°F (set 1954) sits about 48°F above that. When a live reading is available, the live readout just below the record high and low compares it with the temperature typical for that hour this month (estimated from the month's normal high and low), so you can see how unusual the day is rather than guessing.
When did St. Louis set its temperature records?: St. Louis's record high of 115°F was set in 1954 (July 14, 1954), and its record low of -18°F in 1985 (January 20, 1985). Both are pulled from the station's full daily record going back to 1938, so they reflect the true extremes rather than a recent or partial sample.
Has St. Louis been getting hotter?: Yes — St. Louis's annual mean temperature has trended about 3.5°F warmer since 1939 (+0.40°F per decade, fitted to the complete years of 1939–2025). That gradual shift in the average is separate from the all-time records above, which mark the single most extreme days rather than the trend, but a warming baseline is part of why recent years more often brush up against the record-high end.