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Castries vs Belfast
Comparing Castries change · Belfast change
Castries is the warmer of the two — about 31°F on the annual average; Castries is the wetter, with 39 in more rain a year, and Castries the sunnier.
How the seasons compare
The differences between Castries and Belfast, in everyday terms.
Summers
Castries has far hotter summers
Castries: Warm
Belfast: Mild
Winters
Castries has far milder winters
Castries: Stays warm
Belfast: Chilly
Rain & snow
Castries is wetter
Castries: Very wet
Belfast: Moderate rainfall
Sky
Castries is far sunnier
Castries: Fairly sunny
Belfast: Often grey
Month-by-month charts
Temperature
Castries is the warmer of the two — about 31°F on the annual average.
Precipitation
Castries is the wetter — about 39 in more across the year.
Clear skies
Castries has the clearer skies — the higher line.
Exact monthly numbers
Tap a metric to open its full table. Desktop shows all twelve months; on a phone each metric splits into Jan–Jun and Jul–Dec.
Avg high (°F) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 80 | 80 | 80 | 82 | 83 | 83 | 83 | 84 | 84 | 83 | 83 | 81 |
| Belfast | 46 | 48 | 51 | 55 | 60 | 64 | 67 | 66 | 62 | 56 | 51 | 47 |
| Difference | -34 | -32 | -30 | -27 | -23 | -19 | -17 | -18 | -22 | -27 | -32 | -34 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 80 | 80 | 80 | 82 | 83 | 83 |
| Belfast | 46 | 48 | 51 | 55 | 60 | 64 |
| Difference | -34 | -32 | -30 | -27 | -23 | -19 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 83 | 84 | 84 | 83 | 83 | 81 |
| Belfast | 67 | 66 | 62 | 56 | 51 | 47 |
| Difference | -17 | -18 | -22 | -27 | -32 | -34 |
Avg low (°F) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 78 | 77 | 78 | 79 | 80 | 81 | 81 | 82 | 82 | 82 | 81 | 79 |
| Belfast | 36 | 36 | 38 | 41 | 45 | 50 | 53 | 53 | 50 | 45 | 41 | 37 |
| Difference | -42 | -41 | -40 | -38 | -35 | -31 | -28 | -29 | -32 | -36 | -40 | -42 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 78 | 77 | 78 | 79 | 80 | 81 |
| Belfast | 36 | 36 | 38 | 41 | 45 | 50 |
| Difference | -42 | -41 | -40 | -38 | -35 | -31 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 81 | 82 | 82 | 82 | 81 | 79 |
| Belfast | 53 | 53 | 50 | 45 | 41 | 37 |
| Difference | -28 | -29 | -32 | -36 | -40 | -42 |
Precipitation (in) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 4.5 | 3 | 2.6 | 3.5 | 4.5 | 5.3 | 8.5 | 11.5 | 8.8 | 9.7 | 9.6 | 5.9 |
| Belfast | 3.5 | 2.9 | 2.9 | 2.5 | 2.7 | 2.9 | 3 | 3.4 | 2.9 | 3.9 | 4.2 | 3.8 |
| Difference | -0.9 | -0.1 | +0.3 | -1 | -1.8 | -2.3 | -5.5 | -8 | -5.9 | -5.8 | -5.4 | -2.1 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 4.5 | 3 | 2.6 | 3.5 | 4.5 | 5.3 |
| Belfast | 3.5 | 2.9 | 2.9 | 2.5 | 2.7 | 2.9 |
| Difference | -0.9 | -0.1 | +0.3 | -1 | -1.8 | -2.3 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 8.5 | 11.5 | 8.8 | 9.7 | 9.6 | 5.9 |
| Belfast | 3 | 3.4 | 2.9 | 3.9 | 4.2 | 3.8 |
| Difference | -5.5 | -8 | -5.9 | -5.8 | -5.4 | -2.1 |
Cloud cover (%) Belfast runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 38 | 39 | 42 | 49 | 52 | 59 | 50 | 46 | 51 | 51 | 46 | 41 |
| Belfast | 79 | 79 | 78 | 76 | 73 | 77 | 78 | 77 | 76 | 78 | 79 | 78 |
| Difference | +40 | +40 | +37 | +27 | +21 | +18 | +28 | +30 | +25 | +27 | +32 | +38 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 38 | 39 | 42 | 49 | 52 | 59 |
| Belfast | 79 | 79 | 78 | 76 | 73 | 77 |
| Difference | +40 | +40 | +37 | +27 | +21 | +18 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 50 | 46 | 51 | 51 | 46 | 41 |
| Belfast | 78 | 77 | 76 | 78 | 79 | 78 |
| Difference | +28 | +30 | +25 | +27 | +32 | +38 |
Relative humidity (%) Belfast runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 76 | 75 | 75 | 76 | 77 | 79 | 79 | 79 | 79 | 79 | 79 | 77 |
| Belfast | 90 | 90 | 89 | 86 | 85 | 85 | 86 | 87 | 88 | 88 | 90 | 91 |
| Difference | +15 | +15 | +14 | +10 | +7 | +7 | +8 | +8 | +9 | +9 | +11 | +14 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 76 | 75 | 75 | 76 | 77 | 79 |
| Belfast | 90 | 90 | 89 | 86 | 85 | 85 |
| Difference | +15 | +15 | +14 | +10 | +7 | +7 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 79 | 79 | 79 | 79 | 79 | 77 |
| Belfast | 86 | 87 | 88 | 88 | 90 | 91 |
| Difference | +8 | +8 | +9 | +9 | +11 | +14 |
How both climates are changing
Both cities are warming. Each city has its own warming trend; see its trends page for the year-by-year detail. Castries trends → · Belfast trends →
Both cities' Köppen climate types are projected to hold steady through 2099 (SSP2-4.5).
Methodology & sources
Castries
Temperature — modelled for this location from ERA5-Land reanalysis, a ~9 km global grid, because no long-record weather station is close enough to use.
Precipitation — 1991–2020 normals computed from 10 years of daily observations at LE Lamentin, a weather station, about 66 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.
Belfast
Temperature & precipitation — 1991–2020 normals computed from 29 years of daily observations at Stormont Castle, a weather station, about 6 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.
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