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Redwood City in September

Find out everything about the water temperature in Redwood City in September. Average, minimum and maximum recorded temperatures as well as daily temperature in September for the last two years. Compare the current month's sea temperature data with other months of the year.
Water temperature in September
Minimum:

57.4 °F

Average:

66.2 °F

Maximum:

74.5 °F

Sea water temperature in Redwood City in September

In the city of Redwood City, the month of September is somewhat comfortable for swimming. The minimum recorded temperature during this month was 57.4°F on September 14, 2016, with an average temperature being 66.2°F and a maximum temperature reaching 74.5°F on September 9, 2022.

While some may find it enjoyable for a brief swim, others might consider it a bit too cold for extended periods in the water. In September, the sea temperature remains relatively stable. The average temperature stays close to 66.2°F throughout the month, with minimal changes.
Date 10 years average 2025 2024
Sep 1 66.6°F 70.4°F 70.2°F
Sep 2 66.5°F 70.4°F 70.1°F
Sep 3 66.5°F 71.1°F 68.5°F
Sep 4 66.4°F 71.4°F 68.5°F
Sep 5 66.7°F 71.5°F 70.4°F
Sep 6 66.7°F 70.2°F 70.4°F
Sep 7 66.7°F 69.4°F 71.1°F
Sep 8 66.7°F 69.9°F 70.4°F
Sep 9 66.8°F 69.7°F 69.8°F
Sep 10 66.6°F 68.8°F 69.9°F
Sep 11 66.1°F 68.8°F 69.3°F
Sep 12 65.7°F 67.7°F 69.3°F
Sep 13 65.6°F 68.1°F 67.5°F
Sep 14 66.0°F 68.4°F 68.5°F
Sep 15 66.4°F 70.0°F 69.3°F
Sep 16 66.3°F 69.8°F 68.7°F
Sep 17 66.1°F 70.9°F 68.2°F
Sep 18 66.2°F 70.9°F 66.1°F
Sep 19 66.1°F 71.5°F 65.8°F
Sep 20 65.8°F 70.7°F 65.7°F
Sep 21 65.6°F 69.4°F 66.4°F
Sep 22 65.7°F 69.7°F 66.0°F
Sep 23 65.7°F 70.3°F 64.9°F
Sep 24 65.9°F 70.7°F 66.6°F
Sep 25 66.3°F 70.9°F 68.3°F
Sep 26 66.4°F 70.6°F 68.4°F
Sep 27 66.6°F 70.7°F 69.6°F
Sep 28 66.1°F 70.3°F 68.3°F
Sep 29 66.0°F 69.4°F 69.9°F
Sep 30 65.5°F 68.6°F 69.4°F

Sea water temperature in Redwood City by month

In an average year, Redwood City offers no days when the water temperature is warm enough to swim comfortably. The warmest water in Redwood City was recorded on September 9, 2022, reaching a 74.5°F. While the coldest temperature occurred on March 3, 2023, dipping to 49.7°F. The average readings by season are 53.7°F in Winter, 58.9°F in Spring, 65.6°F in Summer, and 63.1°F in Autumn. In September, the temperature is higher than August's average of 66.1°F and October's average of 63.7°F.

Popular neighboring cities and resorts

City Water temperature* Distance**
San Jose 53.9°F 21mi
Oakland 54.1°F 22mi
San Francisco 54.6°F 22mi

* current water temperature in this city

** straight line distance from Redwood City