Post Island Beach Sea Water Temperature
A cool beach on the James Bay, warmest around August at about 19°C. Today's reading, 7-day forecast, and monthly averages below.
Post Island Beach water temperature
Invigorating and crisp. Tolerable for active swimming, but chilly for prolonged casual bathing.
7-Day Water Temperature Forecast
Post Island Beach Monthly Water Temperature Averages
Historical monthly climatology. The warmest water in Post Island Beach occurs inJune, July, August, September — peaking at19°C (66.2°F) in August.
Year-Round Water Temperature Curve (°C / °F)
Hover a bar for detailsFull 12-month data table — min / avg / max & swimming comfort
| Month | Min Water Temp | Average Water Temp | Max Water Temp | Swimming Comfort |
|---|---|---|---|---|
| January | 2.7°C | 5.5°C | 8°C | Very Cold (< 16°C) |
| February | 2.3°C | 3.6°C | 5.3°C | Very Cold (< 16°C) |
| March | 1.4°C | 3.8°C | 6.3°C | Very Cold (< 16°C) |
| April | 4°C | 6.2°C | 9.1°C | Very Cold (< 16°C) |
| May | 7.4°C | 10.5°C | 15.1°C | Very Cold (< 16°C) |
| June | 12°C | 15.1°C | 18°C | Very Cold (< 16°C) |
| July | 15.9°C | 18.4°C | 21.7°C | Cool / Refreshing (16°C – 20°C) |
| August | 16.5°C | 19°C | 21.7°C | Cool / Refreshing (16°C – 20°C) |
| SeptemberCurrent | 15.3°C | 17.6°C | 20.9°C | Cool / Refreshing (16°C – 20°C) |
| October | 10.6°C | 14.2°C | 17.1°C | Very Cold (< 16°C) |
| November | 8.5°C | 10.7°C | 13.8°C | Very Cold (< 16°C) |
| December | 5.6°C | 7.9°C | 10.3°C | Very Cold (< 16°C) |
Swimming FAQs for Post Island Beach
Is the sea warm enough to swim in Post Island Beach today?
Typical sea surface temperature in Post Island Beach this time of year is 17.6°C (63.7°F) — classified as Cool / Refreshing (16°C – 20°C). Invigorating and crisp. Tolerable for active swimming, but chilly for prolonged casual bathing. Live readings load automatically.
What are the warmest months for swimming in Post Island Beach?
The highest water temperatures in Post Island Beach typically occur duringJune, July, August, September, when monthly averages reach peak seasonal levels.
What is the typical water temperature in Post Island Beach in September?
Historically in September, water temperatures in Post Island Beach average around17.6°C (63.7°F), fluctuating between a recorded minimum of 15.3°C and a maximum of 20.9°C.