To be sure, the Atlantic Gulf Stream keeps Ireland just right with relatively mild winters and cool summers. Another certainty is the rain, Belfast has a decent share of it, making for some bleak, sunless, wet and wintery days. True to its people, the weather is not without its own mischeivousness with the occasional warm January day or cold July night.
| Low temp (°C) | High temp (°C) | Sunshine (hours) | Rainfall (mm) | Humidity (am) | Humidity (pm) | |
|---|---|---|---|---|---|---|
| Jan | 2 | 6 | 1 | 8.0 | 92 | 87 |
| Feb | 2 | 7 | 2 | 5.2 | 91 | 80 |
| Mar | 3 | 9 | 3 | 5.0 | 88 | 74 |
| Apr | 4 | 12 | 5 | 4.8 | 83 | 69 |
| May | 6 | 15 | 6 | 5.2 | 79 | 66 |
| Jun | 9 | 18 | 6 | 6.8 | 80 | 71 |
| Jul | 11 | 18 | 4 | 9.4 | 84 | 73 |
| Aug | 11 | 18 | 4 | 7.7 | 87 | 75 |
| Sep | 9 | 16 | 4 | 8.0 | 89 | 78 |
| Oct | 7 | 13 | 3 | 8.3 | 91 | 80 |
| Nov | 4 | 9 | 2 | 7.2 | 92 | 85 |
| Dec | 3 | 7 | 1 | 9.0 | 92 | 89 |