What is the hottest day ever recorded in Allentown?

Allentown's hottest day on record reached 105°F, set on July 3, 1966. That is the single most extreme high in the nearest long-term weather station's full daily record — about 42°F hotter than a typical year's average high of 63°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 Allentown?

The all-time record high in Allentown is 105°F, recorded on July 3, 1966. 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 Allentown?

Allentown's coldest day on record bottomed out at -15°F, set on January 21, 1994. 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 Allentown?

The all-time record low in Allentown is -15°F, recorded on January 21, 1994. The gap between that and the 105°F record high — a span of 120°F — is the full range of temperatures Allentown has experienced across its long-term daily record.

Is it normal to be this hot in Allentown?

It depends on how far above Allentown's normal a given day runs. A typical year here averages a daily high near 63°F; the all-time record of 105°F (set 1966) sits about 42°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 Allentown set its temperature records?

Allentown's record high of 105°F was set in 1966 (July 3, 1966), and its record low of -15°F in 1994 (January 21, 1994). Both are pulled from the station's full daily record going back to 1948, so they reflect the true extremes rather than a recent or partial sample.

Has Allentown been getting hotter?

Yes — Allentown's annual mean temperature has trended about 2.5°F warmer since 1948 (+0.32°F per decade, fitted to the complete years of 1948–2025). 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.

Allentown, Pennsylvania Weather Records

The hottest and coldest days Allentown has ever recorded — and how today compares to normal

Allentown’s all-time temperature records

Hottest day on record: 105°Fset July 3, 1966
Coldest day on record: -15°Fset January 21, 1994

That is a 120°F span between the hottest and coldest days Allentown has ever recorded — the full range of what its weather has done across the station’s record back to 1948.

Allentown, PA · Today vs. normal

About typical for 10:15 AM on Sep 21

At 10:15 AM EDT on Sep 21 it was 64°F in Allentown — about the 63°F typical for that hour (estimated from the Sep 21 normal high of 75°F and low of 53°F, interpolated from the monthly normals).

How extreme Allentown’s weather gets

Allentown’s weather is usually mild by its own standards — a typical year averages a daily high near 63°F, and the normal high for September runs about 77°F. The records sit well outside that everyday range. The hottest day on record reached 105°F in 1966 — roughly 42°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, Allentown has bottomed out at -15°F (1994). 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 105°F record is the rare event the record marks.

Frequently asked

What is the hottest day ever recorded in Allentown?: Allentown's hottest day on record reached 105°F, set on July 3, 1966. That is the single most extreme high in the nearest long-term weather station's full daily record — about 42°F hotter than a typical year's average high of 63°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 Allentown?: The all-time record high in Allentown is 105°F, recorded on July 3, 1966. 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 Allentown?: Allentown's coldest day on record bottomed out at -15°F, set on January 21, 1994. 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 Allentown?: The all-time record low in Allentown is -15°F, recorded on January 21, 1994. The gap between that and the 105°F record high — a span of 120°F — is the full range of temperatures Allentown has experienced across its long-term daily record.
Is it normal to be this hot in Allentown?: It depends on how far above Allentown's normal a given day runs. A typical year here averages a daily high near 63°F; the all-time record of 105°F (set 1966) sits about 42°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 Allentown set its temperature records?: Allentown's record high of 105°F was set in 1966 (July 3, 1966), and its record low of -15°F in 1994 (January 21, 1994). Both are pulled from the station's full daily record going back to 1948, so they reflect the true extremes rather than a recent or partial sample.
Has Allentown been getting hotter?: Yes — Allentown's annual mean temperature has trended about 2.5°F warmer since 1948 (+0.32°F per decade, fitted to the complete years of 1948–2025). 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.