Aarau

Planning your day or preparing for a trip? Here you will find the most up-to-date weather information for Aarau, including detailed forecasts and visual charts.

The climate in Aarau can be described as temperate-continental, typical of the Swiss Plateau. The weather here is quite mild and comfortable, without extreme temperature swings, making the city pleasant to visit at any time of year. Distinct seasonality allows tourists to enjoy both warm summers and cool, atmospheric winters.

Summer months, especially July and August, bring warmth with average daytime temperatures around 20–24°C, which is ideal for long walks and sightseeing. Winter in Aarau is usually mild: the average temperature stays just above freezing (around 1–4°C), and severe frosts are rare. Spring and autumn serve as smooth transition periods when Switzerland's nature reveals itself in all its glory.

An important feature of Aarau's weather is the fairly high frequency of precipitation throughout the year. There is no pronounced dry season: rainy or cloudy days are distributed evenly, from 12 to 19 days per month, with May often being the "wettest" month. Travelers are advised to always carry an umbrella or a light raincoat, as short showers are possible even in the height of summer.

The climate in Aarau is characterized by distinct seasonality, offering travelers a variety of weather conditions throughout the year. The summer months—July and August—are traditionally considered the warmest and most comfortable time to visit. During this period, the average daytime temperature reaches a pleasant 24.5°C, creating ideal conditions for long walks and sightseeing without exhausting heat. The coldest month is January, when the average temperature drops to 1.7°C, and night frosts become common.

Summer in the city can be described as moderately warm but not sweltering. Average figures in June, July, and August stay around 18–20°C. However, tourists should take into account noticeable temperature swings during the day: even after a warm sunny day when the air heats up to 23–24°C, the nights bring a noticeable freshness, and the thermometer can drop to 13–15°C. Therefore, a light jacket or sweater will come in handy even in the height of the summer season.

Winter in Aarau is cool but generally mild compared to the high-altitude regions of Switzerland. From December to February, daytime temperatures rarely exceed 5–7°C, and at night there is often a light frost with values around -1°C to 0°C. The shoulder seasons are characterized by a smooth transition: spring begins with a cool March (around 6°C) and gradually warms up toward May, while autumn offers mild warmth in September before cooling down sharply by November.

In Aarau, precipitation is distributed fairly evenly throughout the year, so it is difficult to identify a pronounced dry season. Travelers should be prepared for rain or snow in any month. The Swiss climate in this region is characterized by regular humidity, which contributes to the lush greenery in the parks and surrounding areas.

The winter period, especially December and January, often brings precipitation in the form of snow or sleet as temperatures drop to freezing. December stands out as one of the cloudiest months: statistics show about 18 days with precipitation. At this time of year, it is recommended to have warm, waterproof clothing to comfortably enjoy the winter atmosphere of the old town.

Spring brings gradual warming but also an increase in the frequency of rain. May holds the record for the number of wet days—there can be up to 19 per month. In summer, from June to August, the nature of precipitation changes: warm showers or thunderstorms often occur, which usually pass quickly. Despite the rain, summer remains the warmest time of year.

If you are looking for a period with the lowest probability of precipitation, you should look at February, when about 12 rainy days are recorded, as well as the beginning of autumn. September and October usually offer more stable weather with a moderate amount of precipitation (about 14 days per month), making this a pleasant time for walking and excursions.

When planning a trip to Aarau, it is worth remembering the variability of the local weather and sticking to the principle of layering. Since even in summer, mornings and evenings can be quite brisk, while the air warms up to a comfortable 20–24°C during the day, bring clothes that are easy to combine: T-shirts, light jumpers, and cardigans. This will allow you to quickly adapt to temperature changes throughout the day without returning to your hotel to change.

If your trip is planned for the winter months, when the mercury often drops to 0°C, be sure to pack a warm, windproof jacket or down coat, as well as a hat, scarf, and gloves. In summer, light clothing made of natural fabrics will suffice, but don't forget to grab a windbreaker or a thick sweater in case of a cool breeze. Sunglasses and sunscreen are useful in any season: the sun can be active in summer, and in winter, its rays reflect brightly if it snows.

Pay special attention to footwear and rain protection. Statistics show that precipitation in Aarau is a frequent and regular occurrence throughout the year (up to 15–19 rainy days per month), so a compact umbrella or a high-quality raincoat are essential travel companions. For walking around the city and its surroundings, choose the most comfortable shoes with flat soles, preferably waterproof, as you will be doing a lot of walking while exploring the sights.