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Weather extremes

How extreme does St. Catharines's weather get?

The hottest, coldest, wettest and snowiest days St. Catharines has recorded — the outer limits of what its weather can do, and how far they sit beyond a normal day.

Based on 21 years of daily weather observations (2005–present), from the Welland-Pelham station 24 km away. Updated through May 2026 — an all-time extreme only changes when a more extreme day actually occurs, so some dates are old. That is normal, not stale data.

The four kinds of extreme

The hottest, coldest, wettest and snowiest single days St. Catharines has recorded — each shown against what a normal day that time of year looks like.

🔥 Hottest day
94°F Jul 9, 2020

That is about 14°F hotter than a normal July afternoon in St. Catharines (typical high near 80°F).

The three most extreme on record

1 94°F Jul 9, 2020
2 93°F Aug 4, 2012
3 92°F Aug 8, 2007
❄️ Coldest night
-25°F Feb 16, 2015

About 42°F colder than a normal February night in St. Catharines (typical low near 17°F).

The three most extreme on record

1 -25°F Feb 16, 2015
2 -20°F Jan 24, 2011
3 -18°F Feb 12, 2014
🌧️ Most rain in one day
3.34 in Jun 27, 2015

More rain in a single day than St. Catharines usually gets in the whole month of June (typical June total about 3.1 in).

The three most extreme on record

1 3.34 in Jun 27, 2015
2 2.69 in May 13, 2014
3 2.61 in Oct 28, 2015

How hot and cold it gets, month by month

The shaded band is the normal range of daily temperatures for each month. The dots show the most extreme it has ever been — so you can see how far beyond a normal day the records really sit.

-50°-30°-10°10°30°50°70°90°110° all-time high 94°F JanFebMarAprMayJunJulAugSepOctNovDec
normal range of daily temperatureshottest ever recordedcoldest ever recorded

St. Catharines's record heat sits well above even a hot day for the season — July's 94°F is about 14°F beyond a normal hot afternoon. Its record cold is just as far below a normal winter night — the dots mark how rare each extreme really is.

In plain terms

In a normal year, St. Catharines's warmest days reach the low 80s°F and its coldest nights drop to the high 10s°F. But across the record it has gone as high as 94°F and as low as −25°F. A single day has delivered over 3 inches of rain. Those are the outer edges worth knowing if you are moving here, planning a trip, or thinking about a house.
Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 25 years of daily observations at Port Weller (aut), a weather station, about 9 km from the city centre. The underlying daily records come from NOAA's global station network.

How we build these numbers →