This data the coastal Greater Napanee water temperature today, tomorrow and the upcoming days. Besides, you can also get information about the weather and surf forecast, as well as the data on sunrise / sunset and moonrise / moonset at a given point on any given day.
Water temperature in Greater Napanee today is 20.9°C. Based on our historical data over a period of ten years, the warmest water in this day in the Lake Ontario near Greater Napanee was recorded in 2018 and was 24°C, and the coldest was recorded in 2017 at 20.4°C. Water temperature in Greater Napanee is expected to drop to 20.8°C in the next 10 days. September average water temperature in Greater Napanee is 20.7°C, the minimum temperature is 17.1°C, and the maximum is 24°C.
The swimming season in Greater Napanee lasts from July to September. During those months, Greater Napanee water temperature does not drop below 20°C and therefore suitable for comfortable swimming. The average water temperature in Greater Napanee in winter reaches 2.5°C, in spring 4.7°C, in summer the average temperature rises to 20.2°C, and in autumn it is 15.5°C.
5 September 2025 |
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today temp |
20.9°C |
4 September 2025 |
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yesterday temp |
20.5°C |
Another important indicators for a comfortable holiday on the beach are the presence and height of the waves, as well as the speed and direction of the wind. Please find below data on the swell size for Greater Napanee. We calculate the swell size based on the mean wave height (trough to crest) of each third highest wave. For more information on surf forecasts for the next ten days, please visit sea state forecast Greater Napanee. Data in table shown for 6 September 2025, time in GMT 0 format (you can change the time zone on the sea state forecast page)
0-3 h | 3-6 h | 6-9 h | 9-12 h |
---|---|---|---|
1' 0" | 0' 7" | 0' 5" | 0' 3" |
0.3 m | 0.19 m | 0.12 m | 0.08 m |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
1' 1" | 1' 7" | 1' 7" | 2' 0" |
0.32 m | 0.47 m | 0.48 m | 0.6 m |
Data in a table show Greater Napanee temperature today (6 September 2025). For more information and forecast for a few days, go to the weather forecast Greater Napanee.
0-3 h | 3-6 h | 6-9 h | 9-12 h |
---|---|---|---|
![]() | ![]() | ![]() | ![]() |
13.9°C | 13.9°C | 15.3°C | 16.9°C |
12-15 h | 15-18 h | 18-21 h | 21-24 h |
---|---|---|---|
![]() | ![]() | ![]() | ![]() |
18.7°C | 20.8°C | 21.6°C | 21°C |
You may also be interested in other sections of our site for Greater Napanee: Sunrise and Sunset, Tides
These figures shows the average, minimum and maximum monthly water temperature in Greater Napanee. In addition to the table values, the graph below displays of changes average surface temperature during the year. Values are calculated based on the data over the past 10 years. Using them, you can check the water temperature in Greater Napanee on any day of this period that interests you. Click on the month link and you will see a table for each day, or alternatively you can view the temperature curve of the month and select 2 different years you want to compare, either in a table or as a curve
Month | Avr | Min | Max | |
---|---|---|---|---|
January | 1.7°C | -0.9°C | 5.8°C | cold |
Water temperature in Greater Napanee in January | ||||
February | 0.4°C | -1.1°C | 1.8°C | cold |
Water temperature in Greater Napanee in February | ||||
March | 0.8°C | -0.7°C | 3.6°C | cold |
Water temperature in Greater Napanee in March | ||||
April | 3.6°C | 0°C | 8.8°C | cold |
Water temperature in Greater Napanee in April | ||||
May | 9.6°C | 2.7°C | 17.5°C | cold |
Water temperature in Greater Napanee in May | ||||
June | 16°C | 8.5°C | 22°C | cold |
Water temperature in Greater Napanee in June | ||||
July | 21.6°C | 14.4°C | 26.1°C | warm |
Water temperature in Greater Napanee in July | ||||
August | 22.9°C | 18.9°C | 25.5°C | warm |
Water temperature in Greater Napanee in August | ||||
September | 20.7°C | 17.1°C | 24°C | warm |
Water temperature in Greater Napanee in September | ||||
October | 15.6°C | 10.7°C | 20.2°C | cold |
Water temperature in Greater Napanee in October | ||||
November | 10.2°C | 6.6°C | 14.2°C | cold |
Water temperature in Greater Napanee in November | ||||
December | 5.5°C | 0.6°C | 9.1°C | cold |
Water temperature in Greater Napanee in December |