Weather and Nature

St. Thomas weather

Temperature, rain and wind in St. Thomas (Ontario, Canada), a city of about 38,909 people: how it is right now, hour by hour into tomorrow, the next 7 days and what each month of the year is like.

This page is not in Google’s index: the city is small, or it gets the same forecast as a large city next to it.

Right now

Friday 16 October, 01:00 (America/Toronto)

17 °C

Rain

Feels like

17 °C

Humidity

94%

Wind

27 km/h

S · Beaufort 4

Dew point

16 °C

Cloud cover

100%

Pressure

1,006 hPa

Hour by hour

Next 24 hours, in the city’s local time.

TimeConditionsTemperatureRainWind
01:00Rain17 °C0.3 mm27 km/h
02:00Rain18 °C0.9 mm30 km/h
03:00Rain showers19 °C0.5 mm33 km/h
04:00Cloudy19 °C0.0 mm37 km/h
05:00Light rain19 °C0.1 mm30 km/h
06:00Light rain19 °C0.2 mm26 km/h
07:00Rain19 °C0.7 mm27 km/h
08:00Cloudy18 °C0.0 mm29 km/h
09:00Cloudy17 °C0.0 mm32 km/h
10:00Cloudy16 °C0.0 mm27 km/h
11:00Cloudy16 °C0.0 mm28 km/h
12:00Cloudy14 °C0.0 mm29 km/h
13:00Cloudy14 °C0.0 mm27 km/h
14:00Cloudy13 °C0.0 mm26 km/h
15:00Cloudy12 °C0.0 mm28 km/h
16:00Cloudy12 °C0.0 mm28 km/h
17:00Cloudy11 °C0.0 mm28 km/h
18:00Cloudy10 °C0.0 mm28 km/h
19:00Partly cloudy10 °C0.0 mm28 km/h
20:00Fair9 °C0.0 mm26 km/h
21:00Fair8 °C0.0 mm24 km/h
22:00Clear sky7 °C0.0 mm21 km/h
23:00Clear sky7 °C0.0 mm20 km/h
00:00Fair6 °C0.0 mm20 km/h

Next 7 days

DayConditionsLowHighRain outlook
Fri 16/10Cloudy4 °C19 °Crain possible · 2.7 mm
Sat 17/10Clear sky3 °C10 °Cno rain expected · 0.0 mm
Mon 19/10Clear sky7 °C16 °Cno rain expected · 0.0 mm
Tue 20/10Clear sky5 °C18 °Cno rain expected · 0.0 mm
Wed 21/10Fair6 °C18 °Cno rain expected · 0.0 mm
Thu 22/10Clear sky5 °C18 °Cno rain expected · 0.0 mm
Fri 23/10Partly cloudy8 °C18 °Crain unlikely · 0.6 mm

This column is our own reading: the global model does not publish a probability of precipitation for this region, so we classify the day from the forecast symbol and the total in millimetres. It is not an official probability figure.

Low, high and rain for the next 7 days in St. ThomasChart of the next 7 days in St. Thomas: each day’s vertical band runs from the low to the high (from 3 °C to 19 °C across the week) and the bar at the base shows forecast rain, 3.3 mm in total.05101520°Cmm1942.7Fri 16/10103Sat 17/10167Mon 19/10185Tue 20/10186Wed 21/10185Thu 22/101880.6Fri 23/10

America/Toronto

Our own chart, drawn from the 7-day forecast for St. Thomas shown above.

What each number means

Rain (mm)
1 millimetre of rain is 1 litre of water per square metre. Up to 2 mm in a day is drizzle; from 10 mm it is proper rain; more than 50 mm in a few hours is the amount that floods streets.
Humidity
Relative humidity is how much water vapour the air holds compared with the most it can hold at that temperature. Above 80% sweat evaporates slowly and heat feels worse; below 30% your throat and eyes dry out.
Dew point
The dew point is the temperature at which the air would start to condense. The closer it is to the air temperature, the muggier it feels. Above 20 °C the air already feels heavy.
Feels like
"Feels like" combines temperature, wind and humidity: strong wind carries heat away from the body, so it feels colder than the thermometer; high humidity in the heat makes it feel warmer.
Wind
Wind is given as a speed and the direction it blows from. Up to 20 km/h you barely notice it; at 40 km/h it moves branches and parasols; above 60 km/h it brings down trees and roof tiles.
Cloud cover
Cloud cover as a percentage is how much of the sky is covered. Up to 20% is a clear sky; above 80% the sun barely gets through.
Chance of rain
The model does not publish a probability of precipitation for this region. This column is our own reading: the global model does not publish a probability of precipitation for this region, so we classify the day from the forecast symbol and the total in millimetres. It is not an official probability figure.

Month-by-month climate

In October, St. Thomas averages 11 °C and about 62 mm of rain over the month, on the 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025) climatology.

Warmest month

July

Coldest month

January

Wettest month

July

Driest month

February

MonthMean temperatureRainMean humidity
January-5 °C40 mm87%
February-5 °C38 mm86%
March0 °C43 mm81%
April7 °C56 mm76%
May13 °C66 mm73%
June19 °C68 mm70%
July23 °C70 mm67%
August22 °C55 mm68%
September18 °C69 mm71%
October11 °C62 mm78%
November4 °C50 mm82%
December-2 °C44 mm87%
Average temperature and rainfall month by month in St. ThomasChart of the St. Thomas normals over 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025): the line is each month’s mean temperature, peaking in July and bottoming out in January, and the bars are the month’s average rainfall. The current month is highlighted.-100102030°Cmm020406080JanFebMarAprMayJunJulAugSepOctNovDec
Our own chart, from the NASA POWER 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025) climatology for the coordinates of St. Thomas.

Frequently asked questions

Will it rain tomorrow in St. Thomas?
no rain expected. Rain: 0.0 mm. Low 3 °C, High 10 °C.
What is the temperature in St. Thomas right now?
17 °C, rain. Feels like: 17 °C. Humidity: 94%.
What will the weather be like at the weekend in St. Thomas?
Sat 17/10: clear sky, 3 °C / 10 °C, no rain expected.
Which is the wettest month in St. Thomas?
July — ~70 mm (25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025), NASA POWER).
How far ahead does this St. Thomas forecast go?
This page shows 7 days. The model run used here is from 16/10/2026, 01:18 UTC, and the page fetches a new one every 30 minutes.

Nearby cities

Forecasts for places near St. Thomas:

How to read this page

How to read the min and the max

The week’s high (19 °C) arrives in the afternoon, about two hours after solar noon; the low (3 °C) just before sunrise. Both are air temperature in the shade, two metres above ground — in direct sun or over asphalt a thermometer reads higher.

Where this number comes from

The St. Thomas forecast comes from MET Norway, a partir do ECMWF HRES e, na área nórdica, do MEPS, run of 16/10/2026, 01:18 UTC. The month-by-month climate comes from NASA POWER, climatology of 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025). Both are credited in full at the foot of this page.

What a forecast cannot promise

Out to two days accuracy is high; by day seven the trend matters more than the exact figure. For St. Thomas the model publishes no rain probability, so the expectation column is our reading.

Severe weather warnings

This page is informational. For official warnings of storms, gales or flooding affecting St. Thomas, go to your national weather service through the World Meteorological Organization warning portal.

WMO Severe Weather Information Centre

Understanding the weather and climate of St. Thomas

Is this week in St. Thomas above or below the October normal?

The average of the next 7 days in St. Thomas works out at 11 °C, against a normal of 11 °C for October over 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025). The gap is under one degree, so the week sits squarely inside what the season normally brings.

Within the week the highest maximum lands on Fri 16/10 (19 °C) and the lowest minimum on Sat 17/10 (3 °C). Forecast rain adds up to 3.3 mm, roughly 5% of everything St. Thomas gets in an average October (62 mm). The wettest day is Fri 16/10, with 2.7 mm.

When is the wettest and the driest month in St. Thomas?

On the 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025) climatology, the wettest month in St. Thomas is July, at about 70 mm, and the driest is February, at 38 mm. The two extremes differ by only 1.8 times, which means rain is spread fairly evenly across the year in St. Thomas. For October, the month you are reading this in, the average is 62 mm.

What does the dew point say about how St. Thomas feels?

Right now in St. Thomas the air is at 17 °C with a dew point of 16 °C and relative humidity of 94%. The two sit within a few tenths of each other: the air is all but saturated, which favours fog, dew on the car and laundry that will not dry.

What is the climate of St. Thomas like through the year?

The warmest month in St. Thomas is July (23 °C on average) and the coldest is January (-5 °C), a swing of about 28 °C around an annual mean of 9 °C. A swing above twenty degrees is continental: summer and winter are almost two climates at the same address.

Because St. Thomas lies in the northern hemisphere, at 42.77° north, summer falls in June, July and August, in the middle of the calendar.

How far is St. Thomas from London?

The nearest large city to St. Thomas is London, about 24 km away in a straight line, to the north, with 422,324 inhabitants. In that band the temperature of the two rarely differs by more than a degree or two, but a summer downpour can hit one and miss the other: heat showers are only a few kilometres wide. Being larger, London shows up in more searches, and plenty of people end up reading its forecast assuming it covers St. Thomas.

Words on this page

Apparent temperature

The temperature the body actually feels, rather than the one on the thermometer. It combines air temperature with wind, which carries heat away faster, and humidity, which slows the evaporation of sweat. That is why 30 °C in dry air with a breeze is easier than 28 °C in still, muggy air.

Apparent temperature

Dew point

The temperature air would have to cool to, at constant pressure and moisture, for water to start condensing. The closer the dew point sits to the air temperature, the less room the vapour has and the muggier the day feels.

Dew point

Millimetre of rain

The depth of water rain would leave on a flat surface with no run-off. One millimetre is one litre per square metre, no matter how large the area measured is.

Standard definition by World Meteorological Organization (WMO) · Millimetre of rain

Relative humidity

How much water vapour the air holds compared with the most it could hold at that temperature, as a percentage. Because that ceiling rises with heat, the same amount of vapour reads high at dawn and low in the afternoon.

Relative humidity

Climate normal

The average of a climate element — temperature, rainfall, humidity — computed over a long, standardised period, usually thirty years. It does not predict anything: it says what is typical for that place in that month, and gives you a ruler for calling a week warm or wet.

Standard definition by World Meteorological Organization (WMO) · Climate normal

Forecast model

A program that solves the equations of the atmosphere on a grid of points and steps forward in time from the state observed now. Your city forecast is the model value at the nearest grid point, which is why two neighbouring towns get almost the same numbers.

Standard definition by MET Norway (Meteorologisk institutt) · Forecast model

Model run

The time the model was executed with the latest observations. Every forecast belongs to a run, and runs age: one from six hours ago knows nothing about the shower that started afterwards. It is the first thing to check when two sources disagree.

Standard definition by MET Norway (Meteorologisk institutt) · Model run

See the full weather glossary

Source, model and licence

Model
MET Norway, a partir do ECMWF HRES e, na área nórdica, do MEPS
Model run
16/10/2026, 01:18 UTC
Month-by-month climate
NASA POWER — Climatology (MERRA-2, 2001–2020) — The data was obtained from National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project — Climatology API v2. Dados públicos da NASA, citação obrigatória.
Cities, coordinates and population
Dados de cidades: GeoNames (CC BY 4.0)

The page fetches fresh data every 30 minutes. Informational content. For severe weather warnings, follow your country’s official weather service and civil protection authority.