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Chamonix-Mont-Blanc vs Castries
Comparing Chamonix-Mont-Blanc change · Castries change
Castries is the warmer of the two — about 19°C on the annual average; Castries is the wetter, with 694 mm 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 19°C on the annual average.
Precipitation
Castries is the wetter — about 694 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 3 | 6 | 10 | 14 | 18 | 22 | 24 | 24 | 20 | 15 | 8 | 3 |
| Castries | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 29 | 29 | 29 | 28 | 27 |
| Difference | +24 | +21 | +17 | +13 | +10 | +6 | +4 | +5 | +9 | +14 | +20 | +24 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 3 | 6 | 10 | 14 | 18 | 22 |
| Castries | 27 | 27 | 27 | 28 | 28 | 28 |
| Difference | +24 | +21 | +17 | +13 | +10 | +6 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 24 | 24 | 20 | 15 | 8 | 3 |
| Castries | 28 | 29 | 29 | 29 | 28 | 27 |
| Difference | +4 | +5 | +9 | +14 | +20 | +24 |
Avg low (°C) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | -7 | -6 | -2 | 1 | 5 | 8 | 9 | 9 | 6 | 3 | -2 | -5 |
| Castries | 26 | 25 | 25 | 26 | 27 | 27 | 27 | 28 | 28 | 28 | 27 | 26 |
| Difference | +32 | +31 | +28 | +25 | +22 | +19 | +18 | +18 | +22 | +25 | +29 | +32 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | -7 | -6 | -2 | 1 | 5 | 8 |
| Castries | 26 | 25 | 25 | 26 | 27 | 27 |
| Difference | +32 | +31 | +28 | +25 | +22 | +19 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 9 | 9 | 6 | 3 | -2 | -5 |
| Castries | 27 | 28 | 28 | 28 | 27 | 26 |
| Difference | +18 | +18 | +22 | +25 | +29 | +32 |
Precipitation (mm) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 99 | 78 | 83 | 88 | 124 | 124 | 128 | 130 | 96 | 106 | 99 | 114 |
| Castries | 113 | 76 | 66 | 90 | 114 | 134 | 216 | 291 | 224 | 246 | 243 | 149 |
| Difference | +14 | -2 | -17 | +2 | -10 | +10 | +88 | +161 | +128 | +140 | +144 | +36 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 99 | 78 | 83 | 88 | 124 | 124 |
| Castries | 113 | 76 | 66 | 90 | 114 | 134 |
| Difference | +14 | -2 | -17 | +2 | -10 | +10 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 128 | 130 | 96 | 106 | 99 | 114 |
| Castries | 216 | 291 | 224 | 246 | 243 | 149 |
| Difference | +88 | +161 | +128 | +140 | +144 | +36 |
Snowfall (cm)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 52 | 45 | 21 | 13 | 1 | 0 | 0 | 0 | 0 | 1 | 24 | 56 |
| Castries | — | — | — | — | — | — | — | — | — | — | — | — |
| Difference | — | — | — | — | — | — | — | — | — | — | — | — |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 52 | 45 | 21 | 13 | 1 | 0 |
| Castries | — | — | — | — | — | — |
| Difference | — | — | — | — | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Chamonix-Mont-Blanc | 0 | 0 | 0 | 1 | 24 | 56 |
| 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