Climate and average weather in Blois
In Blois, the summers are warm, showery, and partly cloudy and the winters are cold, snowy, and mostly cloudy.
Over the course of the year, the temperature in Blois typically varies from 2°C to 26°C, and is rarely below -4°C or above 33°C. July is the hottest month of the year, while January is the coldest.
Based on the travel score, the best time of year to visit Blois for warm-weather activities is from mid May to early October.
- Hottest
- Jul
- 26°
- Coldest
- Jan
- 2°
- Wettest
- May
- 69 mm
- Driest
- Jun
- 48 mm
- Rain / yr
- 676 mm
- 120 wet days
- Daylight
- 8.2–15.8 h
- shortest–longest
- Elevation
- 109 m
- 47.6°N
- Clearest
- Aug
- 58% cloud
Blois is French commune and city in Loir-et-Cher, Centre-Val de Loire.
- Air quality
- Excellent
- PM10 14.2 µg/m³ · 2019
- Density
- 1,432/km²
- people per km²
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Blois weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid May to early October.
Temperature through the year
Daily average highs and lows in Blois, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 3.4 months, from June 4 to September 15, with daily high temperatures above 22°C. The hottest month of the year in Blois is July, with an average high of 26°C and low of 15°C.
The cool season lasts 3.6 months, from November 15 to March 5, with daily high temperatures below 11°C. The coldest month of the year in Blois is January, with an average low of 2°C and high of 8°C.
Days typically run about 8°C warmer than nights, with the widest day–night swing (around 11°C) in August.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 8 | 9 | 13 | 16 | 19 | 23 | 26 | 26 | 22 | 17 | 11 | 8 |
| Avg low (°C) | 2 | 2 | 4 | 6 | 10 | 13 | 15 | 15 | 12 | 9 | 5 | 3 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 8 | 2 |
| Feb | 9 | 2 |
| Mar | 13 | 4 |
| Apr | 16 | 6 |
| May | 19 | 10 |
| Jun | 23 | 13 |
| Jul | 26 | 15 |
| Aug | 26 | 15 |
| Sep | 22 | 12 |
| Oct | 17 | 9 |
| Nov | 11 | 5 |
| Dec | 8 | 3 |
How hot and cold Blois really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the coldest nights, wind chill pulls the feels-like down to about -2°C (around February 6), with roughly 93 freezing days a year (feels-like at or below 0°C), worst in February.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 8 | 9 | 13 | 16 | 19 | 23 | 26 | 25 | 22 | 17 | 11 | 8 |
| Air high (°C) | 8 | 9 | 13 | 16 | 19 | 23 | 26 | 26 | 22 | 17 | 11 | 8 |
| Feels-like low (°C) | -1 | -2 | 1 | 4 | 9 | 13 | 15 | 15 | 12 | 7 | 2 | -1 |
| Air low (°C) | 2 | 2 | 4 | 6 | 10 | 13 | 15 | 15 | 12 | 9 | 5 | 3 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 8 | 8 | -1 | 2 |
| Feb | 9 | 9 | -2 | 2 |
| Mar | 13 | 13 | 1 | 4 |
| Apr | 16 | 16 | 4 | 6 |
| May | 19 | 19 | 9 | 10 |
| Jun | 23 | 23 | 13 | 13 |
| Jul | 26 | 26 | 15 | 15 |
| Aug | 25 | 26 | 15 | 15 |
| Sep | 22 | 22 | 12 | 12 |
| Oct | 17 | 17 | 7 | 9 |
| Nov | 11 | 11 | 2 | 5 |
| Dec | 8 | 8 | -1 | 3 |
Average hourly temperature in Blois
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 26°C, and coldest before dawn in January, near 2°C.
Blois weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 8° / 2° | 59 | 11.2 | 0.8 | 8.7 | 1.1 |
| Feb | 9° / 2° | 48 | 9.8 | 1.1 | 9.9 | 1.6 |
| Mar | 13° / 4° | 52 | 10 | 0.3 | 11.6 | 3.4 |
| Apr | 16° / 6° | 54 | 10.6 | 0 | 13.3 | 4.7 |
| May | 19° / 10° | 69 | 11.4 | 0 | 14.9 | 5.8 |
| Jun | 23° / 13° | 48 | 8.5 | 0 | 15.7 | 6.8 |
| Jul | 26° / 15° | 48 | 8.1 | 0 | 15.4 | 7.1 |
| Aug | 26° / 15° | 49 | 8.2 | 0 | 14.1 | 7.0 |
| Sep | 22° / 12° | 48 | 7.8 | 0 | 12.4 | 6.8 |
| Oct | 17° / 9° | 67 | 11 | 0 | 10.6 | 5.0 |
| Nov | 11° / 5° | 65 | 11.5 | 0.1 | 9.1 | 2.6 |
| Dec | 8° / 3° | 69 | 11.8 | 0.7 | 8.3 | 1.3 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Blois gets about 676 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.
The wetter season lasts 5.2 months, from around Oct 1 to Mar 6, peaking in December at about 42% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 21.
May is the wettest month by volume, with 69 mm over about 11 wet days; June is the driest, with 48 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 36 | 35 | 31 | 35 | 37 | 30 | 25 | 26 | 27 | 36 | 38 | 38 |
| Rain days | 11 | 10 | 10 | 11 | 11 | 9 | 8 | 8 | 8 | 11 | 12 | 12 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 36 | 11 |
| Feb | 35 | 10 |
| Mar | 31 | 10 |
| Apr | 35 | 11 |
| May | 37 | 11 |
| Jun | 30 | 9 |
| Jul | 25 | 8 |
| Aug | 26 | 8 |
| Sep | 27 | 8 |
| Oct | 36 | 11 |
| Nov | 38 | 12 |
| Dec | 38 | 12 |
Monthly rainfall
Over a full year, Blois collects about 676 mm of rain across 120 wet days — roughly 56 mm in an average month.
It doesn’t fall evenly. May is the wettest month with 69 mm, while June is the driest at just 48 mm. The three wettest months alone bring about 30% of the year’s total, and some of the cold-season precipitation falls as snow.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 59 | 48 | 52 | 54 | 69 | 48 | 48 | 49 | 48 | 67 | 65 | 69 |
| Rain days | 11 | 10 | 10 | 11 | 11 | 9 | 8 | 8 | 8 | 11 | 12 | 12 |
| Snow days | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Rainfall (mm) | Rain days | Snow days | |
|---|---|---|---|
| Jan | 59 | 11 | 1 |
| Feb | 48 | 10 | 1 |
| Mar | 52 | 10 | 0 |
| Apr | 54 | 11 | 0 |
| May | 69 | 11 | 0 |
| Jun | 48 | 9 | 0 |
| Jul | 48 | 8 | 0 |
| Aug | 49 | 8 | 0 |
| Sep | 48 | 8 | 0 |
| Oct | 67 | 11 | 0 |
| Nov | 65 | 12 | 0 |
| Dec | 69 | 12 | 1 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Blois, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.
The clearer part of the year begins around May 19 and lasts for 4.4 months, ending around September 28. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 47% of the time on average.
The cloudier part of the year begins around September 29 and lasts for 5.4 months, ending around March 12. The cloudiest month is January, when it is overcast or mostly cloudy 77% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 23 | 28 | 33 | 34 | 32 | 37 | 45 | 47 | 39 | 32 | 27 | 25 |
| Cloudier (%) | 77 | 72 | 67 | 66 | 68 | 63 | 55 | 53 | 61 | 68 | 73 | 75 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 23 | 77 |
| Feb | 28 | 72 |
| Mar | 33 | 67 |
| Apr | 34 | 66 |
| May | 32 | 68 |
| Jun | 37 | 63 |
| Jul | 45 | 55 |
| Aug | 47 | 53 |
| Sep | 39 | 61 |
| Oct | 32 | 68 |
| Nov | 27 | 73 |
| Dec | 25 | 75 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 16, brings about 15 h 48 min of light; the shortest, around December 16, only 8 h 12 min — a swing of roughly 7 h 36 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 8.7 | 9.9 | 11.6 | 13.3 | 14.9 | 15.7 | 15.4 | 14.1 | 12.4 | 10.6 | 9.1 | 8.3 |
| Sunrise (AM) | 8:45 | 8:11 | 7:17 | 6:14 | 5:24 | 5:02 | 5:18 | 5:56 | 6:39 | 7:22 | 8:09 | 8:43 |
| Sunset (PM) | 5:23 | 6:07 | 6:52 | 7:36 | 8:18 | 8:47 | 8:43 | 8:01 | 6:59 | 5:57 | 5:11 | 4:58 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 8.7 | 8:45 | 5:23 |
| Feb | 9.9 | 8:11 | 6:07 |
| Mar | 11.6 | 7:17 | 6:52 |
| Apr | 13.3 | 6:14 | 7:36 |
| May | 14.9 | 5:24 | 8:18 |
| Jun | 15.7 | 5:02 | 8:47 |
| Jul | 15.4 | 5:18 | 8:43 |
| Aug | 14.1 | 5:56 | 8:01 |
| Sep | 12.4 | 6:39 | 6:59 |
| Oct | 10.6 | 7:22 | 5:57 |
| Nov | 9.1 | 8:09 | 5:11 |
| Dec | 8.3 | 8:43 | 4:58 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Blois averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 9 days.
The sunnier stretch runs 3.7 months, from around Jun 12 to Oct 2. The sunniest month is July, with roughly 8 sunny days (mixed).
The greyest month is January, down near 4 sunny days — about 53% fewer than the July peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 4 | 5 | 7 | 7 | 5 | 6 | 8 | 8 | 8 | 6 | 4 | 4 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Mixed | Gloomy | Gloomy | Gloomy | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 4 | Gloomy |
| Feb | 5 | Gloomy |
| Mar | 7 | Gloomy |
| Apr | 7 | Gloomy |
| May | 5 | Gloomy |
| Jun | 6 | Gloomy |
| Jul | 8 | Mixed |
| Aug | 8 | Mixed |
| Sep | 8 | Gloomy |
| Oct | 6 | Gloomy |
| Nov | 4 | Gloomy |
| Dec | 4 | Gloomy |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Blois, how humid it feels changes noticeably over the year.
The more humid part of the year lasts 3.6 months, from around May 28 to September 14. The muggiest month is August, when the air feels humid, muggy or worse about 20% of the time.
The most comfortable stretch runs from around September 15 to May 27, and April is the most comfortable month — the air is dry or comfortable 100% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 100 | 100 | 100 | 99 | 85 | 61 | 45 | 47 | 69 | 83 | 98 | 100 |
| Comfortable (%) | 0 | 0 | 0 | 1 | 13 | 28 | 39 | 33 | 25 | 16 | 2 | 0 |
| Humid (%) | 0 | 0 | 0 | 0 | 2 | 10 | 15 | 18 | 5 | 1 | 0 | 0 |
| Muggy (%) | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 2 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | |
|---|---|---|---|---|
| Jan | 100 | 0 | 0 | 0 |
| Feb | 100 | 0 | 0 | 0 |
| Mar | 100 | 0 | 0 | 0 |
| Apr | 99 | 1 | 0 | 0 |
| May | 85 | 13 | 2 | 0 |
| Jun | 61 | 28 | 10 | 1 |
| Jul | 45 | 39 | 15 | 2 |
| Aug | 47 | 33 | 18 | 2 |
| Sep | 69 | 25 | 5 | 0 |
| Oct | 83 | 16 | 1 | 0 |
| Nov | 98 | 2 | 0 | 0 |
| Dec | 100 | 0 | 0 | 0 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Across the year, average wind speed in Blois is typically light breeze, near 13 km/h, and varies little with the seasons.
The windier part of the year lasts 5.8 months, from around Oct 20 to Apr 15. The windiest month is December, averaging about 15 km/h (light breeze).
The calmer part of the year runs from around Apr 16 to Oct 19, with August the calmest month at about 11 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 15 | 14 | 14 | 13 | 12 | 12 | 12 | 11 | 12 | 13 | 14 | 15 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | calm | calm | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 15 | light breeze |
| Feb | 14 | light breeze |
| Mar | 14 | light breeze |
| Apr | 13 | light breeze |
| May | 12 | light breeze |
| Jun | 12 | light breeze |
| Jul | 12 | calm |
| Aug | 11 | calm |
| Sep | 12 | light breeze |
| Oct | 13 | light breeze |
| Nov | 14 | light breeze |
| Dec | 15 | light breeze |
Best time to visit Blois
To characterize how pleasant the weather is in Blois throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late May, Blois is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Blois for general outdoor tourist activities is from mid May to early October, with a peak score in the last week of August.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 1.1 | 1.6 | 3.4 | 4.7 | 5.8 | 6.8 | 7.1 | 7.0 | 6.8 | 5.0 | 2.6 | 1.3 |
| Rating | poor | poor | poor | fair | good | good | good | good | good | fair | poor | poor |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 1.1 | poor |
| Feb | 1.6 | poor |
| Mar | 3.4 | poor |
| Apr | 4.7 | fair |
| May | 5.8 | good |
| Jun | 6.8 | good |
| Jul | 7.1 | good |
| Aug | 7.0 | good |
| Sep | 6.8 | good |
| Oct | 5.0 | fair |
| Nov | 2.6 | poor |
| Dec | 1.3 | poor |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Blois for hot-weather activities is from mid June to early September, with a peak score in the last week of July.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Blois, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around July (highs near 26°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 8°C), pack a warm layer, a heavy coat and rain gear.
In July, Blois sees daytime highs around 26°C and nights near 15°C. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.
UV index (midday) in Blois by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Blois peaks around July 24 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 6 | 7 | 7 | 7 | 5 | 3 | 1 | 1 |
| Level | Low | Low | Moderate | High | High | High | High | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | High |
| May | 6 | High |
| Jun | 7 | High |
| Jul | 7 | High |
| Aug | 7 | High |
| Sep | 5 | Moderate |
| Oct | 3 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Average hourly UV index in Blois
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in July the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 3.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 0 | 0 | 3 | 5.5 | 7 | 7.5 | 8 | 7 | 5 | 0 | 0 | 0 |
| UV ≥ 6 (h/day) | 0 | 0 | 0 | 0 | 2 | 3 | 3.5 | 3 | 0 | 0 | 0 | 0 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 0 | 0 |
| Feb | 0 | 0 |
| Mar | 3 | 0 |
| Apr | 5.5 | 0 |
| May | 7 | 2 |
| Jun | 7.5 | 3 |
| Jul | 8 | 3.5 |
| Aug | 7 | 3 |
| Sep | 5 | 0 |
| Oct | 0 | 0 |
| Nov | 0 | 0 |
| Dec | 0 | 0 |
Growing season
Blois is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about March 18 to November 15 (243 days); outside that window a hard frost is an occasional risk.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 71 | 70 | 87 | 97 | 100 | 100 | 100 | 100 | 100 | 99 | 90 | 75 |
| Frost nights | 31 | 28 | 15 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 16 | 31 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 71 | 31 |
| Feb | 70 | 28 |
| Mar | 87 | 15 |
| Apr | 97 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 99 | 0 |
| Nov | 90 | 16 |
| Dec | 75 | 31 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Blois banks about 1,324 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 0 | 0 | 0 | 31 | 142 | 239 | 315 | 310 | 199 | 87 | 1 | 0 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 0 |
| Feb | 0 |
| Mar | 0 |
| Apr | 31 |
| May | 142 |
| Jun | 239 |
| Jul | 315 |
| Aug | 310 |
| Sep | 199 |
| Oct | 87 |
| Nov | 1 |
| Dec | 0 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Blois receives about 3.4 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.9 and 5.8 kWh/m².
The brighter stretch of the year lasts 6.1 months, from around Mar 20 to Sep 21. The brightest month is June, averaging about 5.7 kWh/m² (bright).
The dimmest month is December, down near 0.9 kWh/m² — roughly 84% less than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 1.1 | 1.9 | 3.2 | 4.6 | 5.4 | 5.7 | 5.7 | 5.0 | 3.7 | 2.2 | 1.3 | 0.9 |
| Level | Dim | Dim | Moderate | Bright | Bright | Bright | Bright | Bright | Moderate | Moderate | Dim | Dim |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 1.1 | Dim |
| Feb | 1.9 | Dim |
| Mar | 3.2 | Moderate |
| Apr | 4.6 | Bright |
| May | 5.4 | Bright |
| Jun | 5.7 | Bright |
| Jul | 5.7 | Bright |
| Aug | 5.0 | Bright |
| Sep | 3.7 | Moderate |
| Oct | 2.2 | Moderate |
| Nov | 1.3 | Dim |
| Dec | 0.9 | Dim |
Where is Blois?
Blois sits at 47.6°N, 1.3°E, 109 m above sea level, in France. The nearest listed city is Vendôme, 30 km away.
Topography around Blois
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Blois.
Within 3 km, the terrain around Blois has only modest variations in elevation — a maximum elevation change of 98 m around an average of 97 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 119 m; within 80 km, significant variations in elevation — a maximum elevation change of 265 m.
The land around Blois is covered by artificial surfaces (41%) and trees (23%) within 3 km, cropland (45%) and trees (35%) within 16 km, and cropland (49%) and trees (37%) within 80 km.
France travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / E
- 230 V · 50 Hz
- Prices
- ≈ 77% of US
- price level, 2025
- GDP per capita
- $48,986
- 2025
- Happiness
- 6.6 / 10
- World Happiness, 2025
- Safe drinking water
- 100%
- of population, 2024
- Homicide rate
- 1.3
- per 100k, 2023
- Road deaths
- 5.1
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 539
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Blois (47.5943°, 1.3291°, elevation 109 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).