Old Greenwich — Water Temperature in October

Water Temperature Range

13°C

minimum

19°C

average

24°C

maximum

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Water Temperature Chart for Month

The chart shows the average daily water temperature for each day of the month based on historical data.

Table of Water Temperatures by Day of the Month for Previous Years

Day	2025	2024	2023	2022
OCT 1	21°C	21°C	23°C	20°C
OCT 2	21°C	22°C	21°C	20°C
OCT 3	20°C	21°C	22°C	20°C
OCT 4	20°C	21°C	22°C	19°C
OCT 5	20°C	19°C	23°C	20°C
OCT 6	20°C	19°C	23°C	19°C
OCT 7	21°C	20°C	23°C	20°C
OCT 8	20°C	19°C	23°C	20°C
OCT 9	20°C	20°C	22°C	19°C
OCT 10	20°C	20°C	22°C	19°C
OCT 11	20°C	20°C	21°C	19°C
OCT 12	19°C	19°C	21°C	18°C
OCT 13	20°C	19°C	22°C	18°C
OCT 14	19°C	19°C	21°C	18°C
OCT 15	19°C	19°C	21°C	18°C
OCT 16	19°C	18°C	21°C	18°C
OCT 17	19°C	18°C	21°C	17°C
OCT 18	19°C	18°C	21°C	17°C
OCT 19	19°C	18°C	21°C	17°C
OCT 20	18°C	17°C	19°C	17°C
OCT 21	18°C	16°C	20°C	17°C
OCT 22	18°C	17°C	20°C	17°C
OCT 23	18°C	17°C	20°C	17°C
OCT 24	18°C	17°C	19°C	18°C
OCT 25	18°C	17°C	19°C	17°C
OCT 26	17°C	17°C	18°C	17°C
OCT 27	18°C	17°C	19°C	17°C
OCT 28	17°C	16°C	19°C	17°C
OCT 29	17°C	17°C	18°C	17°C
OCT 30	17°C	15°C	18°C	17°C
OCT 31	17°C	15°C	18°C	17°C

October: Climate and Swimming Opportunities

Average Night Air Temperature

9°C

Average Day Air Temperature

18°C

Precipitation Amount per Month

101 mm

Number of Rainy Days

Daylight per Day

11 hrs

Sunshine per Day

7 hrs

Average Wind Speed

14 km/h

Average Humidity

66%

At such water and air temperatures, swimming often feels chilly and is best for short swims. Getting out can feel cold, so it helps to have dry clothes ready right away.