Geneva weather by month — averages, rainfall & climate trends
Compressed between Lake Geneva, the Jura range and the foothills of the Alps, Geneva has an oceanic climate shaped as much by its mountain neighbours as by the Atlantic — with cool winters, the sharp Bise northeast wind, and summers warm enough to push toward 40°C. Average temperatures and rainfall by month, a climate graph, today's conditions versus the long-term average, and how the climate has shifted since 1940 — all on one page for Geneva, Switzerland.
Today vs average
+3.3°Cmuch warmer than usual
How it’s changed
Right now
What it's doing today vs the historical average for this date.
Right now
17.3°
29°16°
30°17°28°17°
25°18°27°17°30°20°34°21°On this date — July 23
Warmer than usual · 3.3°C above the average high
- Record high: 34.6° · 2019
- Record low: 11.0° · 2012
- One year ago: 25.3°
Every July 23 in history — coldest to hottest
Dots show daily highs (top) and lows (bottom) for each July 23 on record (n = 87). Outlined dots are today's forecast.
Area we sample
Each city's history comes from one ERA5 grid cell — about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.
Location & data
Historical weather for Geneva is sampled from the ECMWF ERA5 reanalysis at 46.20°N, 6.15°E, with daily records since 1940.
- Coordinates
- 46.20°N, 6.15°E
- Time zone
- Europe/Zurich
- Period
- 1940–2026
- Data source
- ERA5 (ECMWF)
Last 30 days
31 of the last 31 days were warmer than the historical average for that date. Average difference: +6.1°C.
Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.
This date over the years
One dot per year — the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis — modelled estimates, not station readings.
Weather by month
Average temperatures and rainfall for each month — what a typical year looks like, from the full record.Climate overview
Geneva occupies the southwestern end of Lake Geneva, where the Rhône River exits the lake, nestled between three mountain ranges: the Jura to the northwest, the Vuache to the south and the Salève to the southeast. Its oceanic climate (Köppen Cfb) brings cool winters, relatively warm summers and rain distributed through the year, with autumn slightly wetter than the other seasons. The lake moderates winter temperatures near the water's edge, while the surrounding mountains give the city rapid access to true Alpine conditions.
The Bise, a cold northeast wind funnelled through the Geneva basin, is a defining winter weather feature that can produce severe frost and icing. In July 2015, during an exceptional European heatwave, Geneva registered its highest recorded temperature, approaching 40°C — a threshold now tested several times as European heatwaves have grown more frequent and intense. The city's position at the intersection of Atlantic, Mediterranean and Alpine climate systems means the weather can change rapidly and dramatically within a single day.
The warmest month is July, with a daily mean around 20.2°C and typical afternoon highs of 24.8°C. In a typical recent year, around 20 days reach 30°C or more. The coolest month is January, when daily means fall to about 1.8°C and overnight lows sit around -1.5°C.
The yearly total for Geneva comes to about 1445 mm; monthly amounts range from 107 mm in February up to 142 mm in May. A typical year brings rain or snow on around 165 days.
Comparing the record's first decade with its most recent one, Geneva now averages 2.8°C warmer than it did in the 1940s. Frost days have thinned out, from around 95 a year in the first decade to about 30 now.
Climate graph (climograph)
July is the warmest month, January the coolest — a yearly swing of 18°C. Wettest month: May (~142 mm). Whole year averages ~1445 mm of rain.
Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).
Monthly wind
Average daily peak wind at 10 m, by month.
Monthly solar energy
Average daily incoming solar energy in megajoules per square metre — a measured proxy for how sunny the month is.
Geneva month by month — what to expect
Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.
| Month | Avg high | Avg low | Rain | Daylight | Record high | Record low |
|---|---|---|---|---|---|---|
| January | 5.3° | -1.5° | 120 mm | 8.8 h | 17.8° (2023) | -19.7° (1942) |
| February | 7.1° | -0.5° | 107 mm | 10.1 h | 19.8° (2021) | -19.9° (1940) |
| March | 11.1° | 2.1° | 110 mm | 11.6 h | 23.6° (2021) | -17.1° (1971) |
| April | 15.0° | 5.2° | 114 mm | 13.3 h | 28.0° (2024) | -7.1° (1956) |
| May | 19.0° | 9.4° | 142 mm | 14.8 h | 31.8° (2009) | -0.4° (1945) |
| June | 22.5° | 13.2° | 133 mm | 15.6 h | 35.9° (2022) | 3.0° (1962) |
| July | 24.8° | 15.1° | 120 mm | 15.2 h | 38.8° (2015) | 6.5° (1962) |
| August | 24.3° | 14.7° | 128 mm | 14.0 h | 38.2° (2025) | 5.0° (1940) |
| September | 20.9° | 11.7° | 111 mm | 12.3 h | 31.4° (1949) | 1.8° (1971) |
| October | 16.2° | 8.0° | 109 mm | 10.6 h | 27.5° (2023) | -6.0° (1941) |
| November | 10.0° | 3.0° | 126 mm | 9.2 h | 21.3° (1970) | -11.9° (1998) |
| December | 6.2° | -0.3° | 126 mm | 8.4 h | 17.5° (2022) | -21.9° (1941) |
How it has changed
Year-by-year signals from 1940 to today.Climate stripes
Annual mean shifted from 1940–1949 to 2016–2025 by +2.8°C.
Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer
Annual mean temperature
Long-term trend: +0.35°C per decade.
One point per year — the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis — modelled estimates, not station readings.
Seasonal warming
Dec–Feb is warming fastest: +0.56°C per decade.
Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis — modelled estimates, not station readings.
Hot days vs frost days
Days ≥ 30°C per year: 4.6 early in the record → 22.0 recently. Frost days: 94 → 31.
Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.
Yearly hot & cold extremes
All-time high in 2015, all-time low in 1941: 38.8°C / -21.9°C.
One point per year — the single hottest and coldest day recorded that year.
Annual rainfall
~1445 mm/year on average. Last decade ran +3% vs that average. Long-term trend: +32 mm per decade.
One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).
Day-by-day grid
Each tiny square is one calendar day across the full record — ~30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).