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Siena vs Castries
Comparing Siena change · Castries change
Castries is the warmer of the two — about 14°C on the annual average; Castries is the wetter, with 1098 mm more rain a year, and Castries the sunnier.
How the seasons compare
The differences between Siena and Castries, in everyday terms.
Summers
Siena has hotter summers
Siena: Hot
Castries: Warm
Winters
Castries has far milder winters
Siena: Chilly
Castries: Stays warm
Rain & snow
Castries is much wetter
Siena: Moderate rainfall
Castries: Very wet
Sky
Castries is sunnier
Siena: Partly cloudy
Castries: Fairly sunny
Month-by-month charts
Temperature
Castries is the warmer of the two — about 14°C on the annual average.
Precipitation
Castries is the wetter — about 1098 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Siena | 9 | 11 | 15 | 19 | 23 | 28 | 31 | 32 | 26 | 20 | 14 | 10 |
| Castries | 27 | 27 | 27 | 28 | 28 | 28 | 28 | 29 | 29 | 29 | 28 | 27 |
| Difference | +17 | +16 | +12 | +9 | +5 | — | -3 | -3 | +3 | +9 | +14 | +18 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Siena | 9 | 11 | 15 | 19 | 23 | 28 |
| Castries | 27 | 27 | 27 | 28 | 28 | 28 |
| Difference | +17 | +16 | +12 | +9 | +5 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Siena | 31 | 32 | 26 | 20 | 14 | 10 |
| Castries | 28 | 29 | 29 | 29 | 28 | 27 |
| Difference | -3 | -3 | +3 | +9 | +14 | +18 |
Avg low (°C) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Siena | 0 | 0 | 3 | 6 | 10 | 13 | 15 | 16 | 12 | 9 | 5 | 1 |
| Castries | 26 | 25 | 25 | 26 | 27 | 27 | 27 | 28 | 28 | 28 | 27 | 26 |
| Difference | +25 | +25 | +22 | +21 | +17 | +14 | +12 | +12 | +16 | +19 | +22 | +25 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Siena | 0 | 0 | 3 | 6 | 10 | 13 |
| Castries | 26 | 25 | 25 | 26 | 27 | 27 |
| Difference | +25 | +25 | +22 | +21 | +17 | +14 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Siena | 15 | 16 | 12 | 9 | 5 | 1 |
| Castries | 27 | 28 | 28 | 28 | 27 | 26 |
| Difference | +12 | +12 | +16 | +19 | +22 | +25 |
Precipitation (mm) Castries runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Siena | 53 | 57 | 64 | 71 | 74 | 53 | 42 | 43 | 96 | 109 | 121 | 82 |
| Castries | 113 | 76 | 66 | 90 | 114 | 134 | 216 | 291 | 224 | 246 | 243 | 149 |
| Difference | +60 | +19 | +3 | +18 | +39 | +81 | +174 | +248 | +128 | +138 | +122 | +68 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Siena | 53 | 57 | 64 | 71 | 74 | 53 |
| Castries | 113 | 76 | 66 | 90 | 114 | 134 |
| Difference | +60 | +19 | +3 | +18 | +39 | +81 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Siena | 42 | 43 | 96 | 109 | 121 | 82 |
| Castries | 216 | 291 | 224 | 246 | 243 | 149 |
| Difference | +174 | +248 | +128 | +138 | +122 | +68 |
Cloud cover (%) Siena runs higher most of the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Siena | 65 | 61 | 62 | 65 | 62 | 50 | 36 | 39 | 53 | 62 | 69 | 65 |
| Castries | 38 | 39 | 42 | 49 | 52 | 59 | 50 | 46 | 51 | 51 | 46 | 41 |
| Difference | -27 | -23 | -20 | -15 | -10 | +9 | +14 | +8 | -2 | -11 | -23 | -24 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Siena | 65 | 61 | 62 | 65 | 62 | 50 |
| Castries | 38 | 39 | 42 | 49 | 52 | 59 |
| Difference | -27 | -23 | -20 | -15 | -10 | +9 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Siena | 36 | 39 | 53 | 62 | 69 | 65 |
| Castries | 50 | 46 | 51 | 51 | 46 | 41 |
| Difference | +14 | +8 | -2 | -11 | -23 | -24 |
Relative humidity (%) Varies through the year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Siena | 91 | 86 | 82 | 78 | 73 | 63 | 54 | 55 | 68 | 80 | 89 | 91 |
| Castries | 76 | 75 | 75 | 76 | 77 | 79 | 79 | 79 | 79 | 79 | 79 | 77 |
| Difference | -15 | -12 | -7 | -2 | +4 | +16 | +25 | +24 | +11 | -1 | -10 | -14 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Siena | 91 | 86 | 82 | 78 | 73 | 63 |
| Castries | 76 | 75 | 75 | 76 | 77 | 79 |
| Difference | -15 | -12 | -7 | -2 | +4 | +16 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Siena | 54 | 55 | 68 | 80 | 89 | 91 |
| Castries | 79 | 79 | 79 | 79 | 79 | 77 |
| Difference | +25 | +24 | +11 | -1 | -10 | -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. Siena trends → · Castries trends →
Methodology & sources
Siena
Temperature & precipitation — the official 1991–2020 climate normals from the WMO's CLINO 1991–2020 collection, measured at Arezzo, about 45 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.
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.
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