Portstewart — Water Temperature in January
Water Temperature Range
7°C
minimum
9°C
average
11°C
maximum
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 | 2026 | 2025 | 2024 | 2023 |
|---|---|---|---|---|
| JAN 1 | 9°C | 10°C | 10°C | 8°C |
| JAN 2 | 10°C | 10°C | 9°C | 7°C |
| JAN 3 | 10°C | 10°C | 9°C | 10°C |
| JAN 4 | 10°C | 10°C | 9°C | 10°C |
| JAN 5 | 10°C | 10°C | 9°C | 9°C |
| JAN 6 | 10°C | 10°C | 9°C | 9°C |
| JAN 7 | 10°C | 10°C | 9°C | 9°C |
| JAN 8 | 10°C | 10°C | 9°C | 10°C |
| JAN 9 | 10°C | 10°C | 9°C | 10°C |
| JAN 10 | 9°C | 10°C | 9°C | 9°C |
| JAN 11 | 10°C | 10°C | 9°C | 9°C |
| JAN 12 | 9°C | 10°C | 8°C | 9°C |
| JAN 13 | 9°C | 9°C | 8°C | 9°C |
| JAN 14 | 8°C | 9°C | 9°C | 9°C |
| JAN 15 | 9°C | 8°C | 8°C | 9°C |
| JAN 16 | 9°C | 8°C | 9°C | 9°C |
| JAN 17 | 9°C | 8°C | 9°C | 9°C |
| JAN 18 | 9°C | 9°C | 9°C | 9°C |
| JAN 19 | 9°C | 9°C | 9°C | 8°C |
| JAN 20 | 9°C | 9°C | 9°C | 8°C |
| JAN 21 | 9°C | 9°C | 8°C | 8°C |
| JAN 22 | 9°C | 9°C | 8°C | 8°C |
| JAN 23 | 9°C | 9°C | 8°C | 8°C |
| JAN 24 | 8°C | 9°C | 8°C | 8°C |
| JAN 25 | 9°C | 9°C | 8°C | 9°C |
| JAN 26 | 9°C | 9°C | 8°C | 8°C |
| JAN 27 | 9°C | 9°C | 8°C | 8°C |
| JAN 28 | 9°C | 9°C | 8°C | 8°C |
| JAN 29 | 9°C | 9°C | 8°C | 8°C |
| JAN 30 | 9°C | 9°C | 9°C | 8°C |
| JAN 31 | 9°C | 9°C | 8°C | 8°C |
January: Climate and Swimming Opportunities
Average Night Air Temperature
3°C
Average Day Air Temperature
8°C
Precipitation Amount per Month
122 mm
Number of Rainy Days
19
Daylight per Day
8 hrs
Sunshine per Day
1 hrs
Average Wind Speed
23 km/h
Average Humidity
90%
At such water and air temperatures, swimming is extremely harsh and generally not enjoyable. The risk of rapid chilling is high, so most people avoid entering the water.