Question 1

Which months had the most sunshine in St. Gallen in 2025?

Accepted Answer

June was the sunniest month in St. Gallen in 2025, recording 357.2 hours of sunshine, followed by August with 319.2 hours and July with 258.5 hours. The summer months clearly dominate the city's sunshine calendar.

Across the full year, St. Gallen accumulated 2,304.4 hours of sunshine. The three summer months (June to August) alone delivered roughly 935 hours, about 41% of the annual total. June averaged close to 11.9 hours of sunshine per day, coinciding with warm conditions: a mean temperature of 19.3°C (66.7°F) and highs reaching 31.4°C (88.5°F).

At the other end of the scale, February was the gloomiest month in St. Gallen with just 66.9 hours of sunshine, while January (103.8 hours) and December (96.9 hours) were also notably dim. Spring offered a strong early boost too, with April reaching 257.6 hours.

For visitors and residents, this means the best stretch for sun-dependent plans in St. Gallen, such as hiking, lake outings, or sightseeing, runs from late spring through summer. Keep in mind that the sunniest summer months were not the driest: July was both bright and the wettest month of 2025, so afternoon showers can still interrupt otherwise sunny days. If you want reliable daylight with milder temperatures, April and May are excellent alternatives in St. Gallen, combining over 225 hours of sunshine each with comfortable conditions.

Question 2

How much rainfall did St. Gallen receive in 2025?

Accepted Answer

St. Gallen received approximately **1,735 mm (68.3 inches)** of total precipitation in 2025, confirming its reputation as one of Switzerland's wetter cities thanks to its alpine foothill setting at 690 m elevation.

Rainfall was spread unevenly across the year, averaging about 145 mm (5.7 inches) per month. The wettest stretch came in summer (June to August 2025), which alone delivered 758.7 mm (29.9 inches) — nearly 44% of the entire year's total. July 2025 stood out as by far the rainiest month with a remarkable 381.2 mm (15.0 inches), accounting for 22% of all the precipitation St. Gallen saw during the year.

The driest months were concentrated in late winter and early spring. December 2025 was the driest of all with just 28.5 mm (1.1 inches), followed by April at 44.1 mm (1.7 inches) and March at 49.0 mm (1.9 inches). Autumn (September to November 2025) added a further 449.9 mm (17.7 inches).

For visitors and residents, this means St. Gallen's heaviest rain in 2025 fell during the warm summer months, often as intense thunderstorms rather than steady drizzle. If you are planning outdoor activities, the cooler, drier spring weeks of March and April offered the most reliable conditions. Overall, the 2025 data shows that while St. Gallen sees plenty of moisture year-round, summer is decisively the wettest season and should be factored into any travel or event planning.

Question 3

What were the temperature extremes in St. Gallen in 2025?

Accepted Answer

St. Gallen swung from a high of **31.6°C (88.9°F)** to a low of **−11.6°C (11.1°F)** in 2025, giving the city a full annual temperature range of 43.2°C (77.8°F-degrees).

The hottest day arrived on **2 July 2025**, when the thermometer in St. Gallen peaked at 31.6°C (88.9°F). The coldest reading came surprisingly late, on the night of **23 November 2025**, when temperatures dropped to −11.6°C (11.1°F). Across the whole year, St. Gallen averaged a mild 9.4°C (49.0°F).

A few more data points from 2025 round out the picture:

- **6 days** climbed to 30°C (86°F) or hotter, and **42 days** reached at least 25°C (77°F)
- **98 frost days** saw the temperature fall below 0°C (32°F)
- **13 ice days** stayed below freezing even at their afternoon peak

June was the warmest month with a mean of 19.3°C (66.7°F), while January was the coldest, averaging just 0.7°C (33.3°F).

For visitors and residents alike, this means St. Gallen offers genuinely warm but rarely extreme summers, so lightweight clothing works well from June through August. The high count of frost days, however, is a reminder to pack proper winter gear and prepare for icy mornings if you're heading to the city in the colder months.

Question 4

How windy is St. Gallen, and how does wind speed vary through the year?

Accepted Answer

St. Gallen is a notably calm city, with average wind speeds of just 7.3 km/h (4.5 mph) across 2025 — light enough that most days feel still rather than breezy.

Wind in St. Gallen stayed gentle throughout 2025, but it did pick up in autumn. October was the windiest month of the year, averaging 10.0 km/h (6.2 mph), while December was the calmest at only 4.4 km/h (2.7 mph). On a seasonal basis, spring was the breeziest stretch at 7.9 km/h, closely followed by summer at 7.8 km/h, with winter the most settled at 5.7 km/h.

This light-wind climate goes hand in hand with high humidity. St. Gallen averaged 78.1% relative humidity in 2025, peaking at a damp 92.5% in December and easing to its lowest of 68.6% in June. Sitting at around 690 m elevation in eastern Switzerland, the city often holds onto moist, stable air, especially in the cooler months.

For visitors and residents, these conditions are mostly good news. The gentle winds mean outdoor dining, cycling, and city walks rarely get disrupted by gusty weather, and warm-season days in St. Gallen stay comfortable rather than blustery. The main trade-off is the persistent dampness in late autumn and winter, when high humidity and low wind can make cold days feel rawer and keep morning fog and mist lingering longer.

Question 5

Which months are the most and least humid in St. Gallen?

Accepted Answer

St. Gallen is most humid in December and least humid in early summer, with December 2025 being the dampest month at 92.5% average relative humidity and June 2025 the driest air at 68.6%. Across the full year, the city averaged a fairly high 78.1% relative humidity.

Humidity in St. Gallen follows a clear seasonal rhythm. The cold half of the year stays noticeably damp: autumn (September–November 2025) averaged 83.5% and the January–February 2025 winter period averaged 82.9%. In total, five months of 2025 sat at or above 80% humidity, reflecting frequent fog and low cloud at the city's 690 m (2,264 ft) elevation.

The air becomes more comfortable from spring into summer. Spring (March–May 2025) averaged 70.7% and summer (June–August 2025) 72.0%, with June's 68.6% marking the year's lowest reading. The overall spread between the most and least humid months was nearly 24 percentage points.

For visitors, this means St. Gallen feels crisp and drier during late spring and early summer, when warmer temperatures around 19.3°C (66.7°F) pair with lower humidity. By December, with averages near 1.1°C (34.0°F) and humidity above 90%, the air feels raw and damp, often bringing grey, foggy days typical of the eastern Swiss plateau.

Riederen

Saint Gallen

FAQ

Which months had the most sunshine in St. Gallen in 2025?

How much rainfall did St. Gallen receive in 2025?

What were the temperature extremes in St. Gallen in 2025?

How windy is St. Gallen, and how does wind speed vary through the year?

Which months are the most and least humid in St. Gallen?