Home › Compare › Castries vs Boston
Castries vs Boston
Comparing Castries change · Boston change
Castries is the warmer of the two — about 16°C on the annual average; Castries is the wetter, with 855 mm more rain a year, and Castries the sunnier.
How the seasons compare
The differences between Castries and Boston, in everyday terms.
Summers
Summers are nearly the same
Castries: Warm
Boston: Warm
Winters
Castries has far milder winters
Castries: Stays warm
Boston: Cold
Rain & snow
Castries is wetter
Castries: Very wet
Boston: Wet
Sky
Castries is sunnier
Castries: Fairly sunny
Boston: Partly cloudy
Month-by-month charts
Temperature
Castries is the warmer of the two — about 16°C on the annual average.
Precipitation
Castries is the wetter — about 855 mm 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 (°C) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 29 | 29 | 29 | 28 | 27 |
| Boston | 3 | 4 | 8 | 14 | 19 | 25 | 28 | 27 | 23 | 17 | 11 | 6 |
| Difference | -24 | -23 | -19 | -14 | -9 | -4 | -1 | -2 | -6 | -12 | -17 | -22 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 27 | 27 | 27 | 28 | 28 | 28 |
| Boston | 3 | 4 | 8 | 14 | 19 | 25 |
| Difference | -24 | -23 | -19 | -14 | -9 | -4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 28 | 29 | 29 | 29 | 28 | 27 |
| Boston | 28 | 27 | 23 | 17 | 11 | 6 |
| Difference | -1 | -2 | -6 | -12 | -17 | -22 |
Avg low (°C) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 26 | 25 | 25 | 26 | 27 | 27 | 27 | 28 | 28 | 28 | 27 | 26 |
| Boston | -5 | -4 | -0 | 5 | 10 | 15 | 19 | 18 | 15 | 9 | 3 | -2 |
| Difference | -31 | -29 | -26 | -21 | -17 | -12 | -8 | -9 | -13 | -19 | -24 | -28 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 26 | 25 | 25 | 26 | 27 | 27 |
| Boston | -5 | -4 | -0 | 5 | 10 | 15 |
| Difference | -31 | -29 | -26 | -21 | -17 | -12 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 27 | 28 | 28 | 28 | 27 | 26 |
| Boston | 19 | 18 | 15 | 9 | 3 | -2 |
| Difference | -8 | -9 | -13 | -19 | -24 | -28 |
Precipitation (mm) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | 113 | 76 | 66 | 90 | 114 | 134 | 216 | 291 | 224 | 246 | 243 | 149 |
| Boston | 86 | 82 | 106 | 92 | 83 | 99 | 83 | 82 | 90 | 102 | 93 | 109 |
| Difference | -27 | +6 | +40 | +3 | -31 | -35 | -133 | -209 | -134 | -144 | -150 | -40 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 113 | 76 | 66 | 90 | 114 | 134 |
| Boston | 86 | 82 | 106 | 92 | 83 | 99 |
| Difference | -27 | +6 | +40 | +3 | -31 | -35 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 216 | 291 | 224 | 246 | 243 | 149 |
| Boston | 83 | 82 | 90 | 102 | 93 | 109 |
| Difference | -133 | -209 | -134 | -144 | -150 | -40 |
Snowfall (cm)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castries | — | — | — | — | — | — | — | — | — | — | — | — |
| Boston | 36 | 37 | 23 | 4 | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 23 |
| Difference | — | — | — | — | — | — | — | — | — | — | — | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | — | — | — | — | — | — |
| Boston | 36 | 37 | 23 | 4 | 0 | 0 |
| Difference | — | — | — | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | — | — | — | — | — | — |
| Boston | 0 | 0 | 0 | 1 | 2 | 23 |
| Difference | — | — | — | — | — | — |
Cloud cover (%) Boston 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 |
| Boston | 63 | 62 | 62 | 64 | 65 | 63 | 57 | 56 | 55 | 60 | 62 | 63 |
| Difference | +25 | +23 | +20 | +14 | +13 | +5 | +8 | +9 | +4 | +9 | +16 | +22 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 38 | 39 | 42 | 49 | 52 | 59 |
| Boston | 63 | 62 | 62 | 64 | 65 | 63 |
| Difference | +25 | +23 | +20 | +14 | +13 | +5 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 50 | 46 | 51 | 51 | 46 | 41 |
| Boston | 57 | 56 | 55 | 60 | 62 | 63 |
| Difference | +8 | +9 | +4 | +9 | +16 | +22 |
Relative humidity (%) Varies through 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 |
| Boston | 88 | 87 | 83 | 80 | 79 | 79 | 74 | 73 | 74 | 78 | 82 | 86 |
| Difference | +12 | +12 | +9 | +3 | +1 | — | -4 | -6 | -4 | -1 | +2 | +9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Castries | 76 | 75 | 75 | 76 | 77 | 79 |
| Boston | 88 | 87 | 83 | 80 | 79 | 79 |
| Difference | +12 | +12 | +9 | +3 | +1 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Castries | 79 | 79 | 79 | 79 | 79 | 77 |
| Boston | 74 | 73 | 74 | 78 | 82 | 86 |
| Difference | -4 | -6 | -4 | -1 | +2 | +9 |
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 → · Boston 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.
Boston
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Boston (NOAA GHCN station USW00014739), about 4 km from the city centre.
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.
← change Castries · change Boston → · Castries page · Boston page