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Chamonix-Mont-Blanc vs Castries
Comparing Chamonix-Mont-Blanc change · Castries change
Castries is the warmer of the two — about 35°F on the annual average; Castries is the wetter, with 27 in more rain a year, and Castries the sunnier.
How the seasons compare
The differences between Chamonix-Mont-Blanc and Castries, in everyday terms.
Summers
Castries has much hotter summers
Chamonix-Mont-Blanc: Mild
Castries: Warm
Winters
Castries has far milder winters
Chamonix-Mont-Blanc: Cold
Castries: Stays warm
Rain & snow
Castries is wetter
Chamonix-Mont-Blanc: Wet
Castries: Very wet
Sky
Castries is sunnier
Chamonix-Mont-Blanc: Often cloudy
Castries: Fairly sunny
Month-by-month charts
Temperature
Castries is the warmer of the two — about 35°F on the annual average.
Precipitation
Castries is the wetter — about 27 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 38 | 42 | 50 | 57 | 65 | 72 | 76 | 75 | 67 | 59 | 47 | 37 |
| Castries | 80 | 80 | 80 | 82 | 83 | 83 | 83 | 84 | 84 | 83 | 83 | 81 |
| Difference | +42 | +38 | +30 | +24 | +18 | +11 | +7 | +9 | +17 | +24 | +36 | +44 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 38 | 42 | 50 | 57 | 65 | 72 |
| Castries | 80 | 80 | 80 | 82 | 83 | 83 |
| Difference | +42 | +38 | +30 | +24 | +18 | +11 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 76 | 75 | 67 | 59 | 47 | 37 |
| Castries | 83 | 84 | 84 | 83 | 83 | 81 |
| Difference | +7 | +9 | +17 | +24 | +36 | +44 |
Avg low (°F) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 20 | 21 | 28 | 34 | 41 | 47 | 49 | 48 | 43 | 37 | 29 | 23 |
| Castries | 78 | 77 | 78 | 79 | 80 | 81 | 81 | 82 | 82 | 82 | 81 | 79 |
| Difference | +58 | +56 | +50 | +45 | +39 | +34 | +32 | +33 | +39 | +45 | +52 | +57 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 20 | 21 | 28 | 34 | 41 | 47 |
| Castries | 78 | 77 | 78 | 79 | 80 | 81 |
| Difference | +58 | +56 | +50 | +45 | +39 | +34 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 49 | 48 | 43 | 37 | 29 | 23 |
| Castries | 81 | 82 | 82 | 82 | 81 | 79 |
| Difference | +32 | +33 | +39 | +45 | +52 | +57 |
Precipitation (in) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 3.9 | 3.1 | 3.3 | 3.5 | 4.9 | 4.9 | 5 | 5.1 | 3.8 | 4.2 | 3.9 | 4.5 |
| Castries | 4.5 | 3 | 2.6 | 3.5 | 4.5 | 5.3 | 8.5 | 11.5 | 8.8 | 9.7 | 9.6 | 5.9 |
| Difference | +0.6 | -0.1 | -0.7 | +0.1 | -0.4 | +0.4 | +3.5 | +6.3 | +5.1 | +5.5 | +5.7 | +1.4 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 3.9 | 3.1 | 3.3 | 3.5 | 4.9 | 4.9 |
| Castries | 4.5 | 3 | 2.6 | 3.5 | 4.5 | 5.3 |
| Difference | +0.6 | -0.1 | -0.7 | +0.1 | -0.4 | +0.4 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 5 | 5.1 | 3.8 | 4.2 | 3.9 | 4.5 |
| Castries | 8.5 | 11.5 | 8.8 | 9.7 | 9.6 | 5.9 |
| Difference | +3.5 | +6.3 | +5.1 | +5.5 | +5.7 | +1.4 |
Snowfall (in)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 20.5 | 17.8 | 8.2 | 4.9 | 0.3 | 0 | 0 | 0 | 0 | 0.6 | 9.3 | 22 |
| Castries | — | — | — | — | — | — | — | — | — | — | — | — |
| Difference | — | — | — | — | — | — | — | — | — | — | — | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 20.5 | 17.8 | 8.2 | 4.9 | 0.3 | 0 |
| Castries | — | — | — | — | — | — |
| Difference | — | — | — | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 0 | 0 | 0 | 0.6 | 9.3 | 22 |
| Castries | — | — | — | — | — | — |
| Difference | — | — | — | — | — | — |
Cloud cover (%) Chamonix-Mont-Blanc runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 66 | 67 | 69 | 72 | 73 | 65 | 56 | 56 | 60 | 64 | 68 | 68 |
| Castries | 38 | 39 | 42 | 49 | 52 | 59 | 50 | 46 | 51 | 51 | 46 | 41 |
| Difference | -27 | -29 | -27 | -23 | -21 | -6 | -7 | -10 | -9 | -12 | -21 | -27 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 66 | 67 | 69 | 72 | 73 | 65 |
| Castries | 38 | 39 | 42 | 49 | 52 | 59 |
| Difference | -27 | -29 | -27 | -23 | -21 | -6 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 56 | 56 | 60 | 64 | 68 | 68 |
| Castries | 50 | 46 | 51 | 51 | 46 | 41 |
| Difference | -7 | -10 | -9 | -12 | -21 | -27 |
Relative humidity (%) Varies through the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 85 | 86 | 86 | 80 | 78 | 77 | 75 | 73 | 77 | 79 | 84 | 84 |
| Castries | 76 | 75 | 75 | 76 | 77 | 79 | 79 | 79 | 79 | 79 | 79 | 77 |
| Difference | -10 | -12 | -11 | -4 | -1 | +2 | +4 | +6 | +2 | — | -5 | -7 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 85 | 86 | 86 | 80 | 78 | 77 |
| Castries | 76 | 75 | 75 | 76 | 77 | 79 |
| Difference | -10 | -12 | -11 | -4 | -1 | +2 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 75 | 73 | 77 | 79 | 84 | 84 |
| Castries | 79 | 79 | 79 | 79 | 79 | 77 |
| Difference | +4 | +6 | +2 | — | -5 | -7 |
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. Chamonix-Mont-Blanc trends → · Castries trends →
Methodology & sources
Chamonix-Mont-Blanc
Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Chamonix, a weather station, inside the city. 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.
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.
← change Chamonix-Mont-Blanc · change Castries → · Chamonix-Mont-Blanc page · Castries page