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St. ThomasReport this photo · linked, not stored
St. ThomasReport this photo · linked, not stored
Climate guideThirty-year normals for St. Thomas
St. Thomas climate by month
Warm-summer humid continental · DfbBest May · Aug–Sep
Annual mean9°day and night
Seasonal swing26°warmest vs coolest
Precipitation1,036 mm128 wet days a year
42.77° N, 81.18° WElevation 232 mUTC−4 · Eastern Daylight Time
When to goSt. Thomas · weather score
Best timeMay · Aug–Sep
October: high / low15° / 6°
iSummary
What the weather is like
St. Thomas has a warm-summer humid continental climate (Köppen Dfb): warm summers, cold winters and precipitation in every season.
The warmest month is July, when afternoons average 27° and nights 17°. January is the coolest month, with highs of -1° and lows of -8°. The difference between the warmest and the coolest month is about 26°, a large swing typical of continental interiors.
About 1,036 mm of precipitation falls in an average year. July is the wettest month (88 mm, 15 wet days) and February the driest (74 mm, 7 wet days). Cloud cover ranges from 28% in July to 57% in December.
Compared with Ottawa, the capital, St. Thomas is 0.1° cooler on a July afternoon and receives more precipitation over the year.
Year in figures
- Hottest afternoons
- 27° · July
- Coldest nights
- -8° · February
- Wettest month
- July
- Driest month
- February
- Clearest skies
- July · 28% cloud
- Longest day
- 15 h 19 min
- Shortest day
- 9 h 03 min
iiCharts
Twelve months at a glance
Temperature and precipitation
Daily high/low range bars, monthly precipitation columnsTemperature curve
Average high, lowDaylight
Hours between sunrise and sunset on the 15th of each monthiiiData table
Climate normals month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average high | -1° | -1° | 4° | 11° | 18° | 24° | 27° | 26° | 22° | 15° | 8° | 2° |
| Average low | -8° | -8° | -4° | 2° | 9° | 15° | 17° | 16° | 12° | 6° | 1° | -4° |
| Precipitation | 81 mm | 74 mm | 72 mm | 86 mm | 90 mm | 90 mm | 88 mm | 88 mm | 93 mm | 84 mm | 99 mm | 91 mm |
| Wet days (≥1 mm) | 7.8 | 7.2 | 8 | 11 | 11.8 | 14 | 15 | 12.5 | 9 | 13 | 8.8 | 9.5 |
| Cloud cover | 55% | 49% | 45% | 42% | 38% | 32% | 28% | 29% | 33% | 39% | 50% | 57% |
| Daylight | 9h 23 | 10h 34 | 11h 53 | 13h 23 | 14h 38 | 15h 19 | 15h 02 | 13h 57 | 12h 31 | 11h 05 | 9h 46 | 9h 03 |
| Month score | 29 | 33 | 33 | 30 | 69 | 66 | 60 | 68 | 78 | 49 | 29 | 24 |
ivMonth by month
St. Thomas in every month
January29
-1° / -8°
81 mm · 7.8 wet days
February33
-1° / -8°
74 mm · 7.2 wet days
March33
4° / -4°
72 mm · 8 wet days
April30
11° / 2°
86 mm · 11 wet days
May69
18° / 9°
90 mm · 11.8 wet days
June66
24° / 15°
90 mm · 14 wet days
July60
27° / 17°
88 mm · 15 wet days
August68
26° / 16°
88 mm · 12.5 wet days
September78
22° / 12°
93 mm · 9 wet days
October49
15° / 6°
84 mm · 13 wet days
November29
8° / 1°
99 mm · 8.8 wet days
December24
2° / -4°
91 mm · 9.5 wet days