Alton

Planning your day in Alton? Here you will find the most up-to-date weather information, including detailed forecasts and helpful charts.

The climate in Alton, USA, is characterized as temperate with four distinct seasons. The city experiences significant temperature fluctuations throughout the year, which is typical for continental regions. Travelers should expect a variety of weather conditions depending on the timing of their visit.

Summers in Alton are warm and occasionally hot, with peak average temperatures in July reaching 26.3°C and maximum values around 30.9°C. Winters, by contrast, are cold: the average temperature in January drops to 0.4°C, with minimum values falling below freezing. Spring and autumn are transitional seasons with milder temperatures, offering comfortable conditions for visiting.

As for precipitation, it is distributed relatively evenly throughout the year, averaging 2–4 mm per month. The number of days with precipitation ranges from 7 to 13 per month, indicating the absence of a pronounced dry or rainy season. Instead, one can expect periodic but not overly heavy precipitation at any time of year. This creates a predictable pattern of seasonal changes without extreme humidity-related weather events.

The temperature regime in Alton is characterized by a significant annual range, clearly illustrating the transition of four distinct seasons. The amplitude of average monthly temperatures throughout the year exceeds 25°C, testifying to substantial seasonal contrasts between warm summers and cool winters. A characteristic feature of the climate is also the noticeable daily temperature fluctuations: the difference between daytime highs and nighttime lows regularly ranges from approximately 7.7°C (e.g., in January) to 11.1°C (e.g., in April), providing a variety of sensations even within a single day.

The summer months, from June to August, bring warm and occasionally hot weather to Alton. Average daily temperatures during this period fluctuate from 24.9°C (June, August) to 26.3°C (July), with daytime highs often rising above 29°C, and in July, they can exceed 30°C (the average July maximum is 30.9°C). Nights also remain warm, with minimum temperatures around 19.9°C – 21.7°C. The winter period, covering December, January, and February, is characterized by cool and sometimes cold weather. Average temperatures in these months vary from 0.4°C in January (the coldest month) to 4.1°C in December. Night frosts are common, especially in January, when the thermometer drops to an average of -3.5°C. During the day, temperatures usually stay within the range of 4.2°C (January) to 8.2°C (December).

The transitional seasons—spring and autumn—show dynamic temperature changes. In spring, from March to May, there is a steady increase in average daily temperatures: from a cool 8.5°C in March (with nighttime lows around 3.5°C and daytime highs up to 13.5°C), through a moderate 13.3°C in April, to a comfortable 20.1°C in May, when daytime air warms to an average of 24.9°C. In autumn, from September to November, the reverse process occurs: from a still-warm 22.4°C in September (with daytime temperatures up to 27.5°C), the temperature gradually decreases to 15.5°C in October and to 8.0°C in November, when nights become significantly colder (average minimum 3.6°C).

In the city of Alton, precipitation is distributed relatively evenly throughout the year, without a pronounced rainy season or dry period. A characteristic feature is the low overall amount of precipitation, even in the "wettest" months, which indicates that intense rainfall is unlikely here.

The highest amount of precipitation, approximately 4 mm per month, falls in March, May, July, and August. These same months see the maximum number of days with precipitation—up to 13 days in March and May. Given such small amounts, summer precipitation likely consists of very light drizzles or brief, minor showers.

The "driest" months, with precipitation around 2 mm, are September, November, and December. September also records the fewest days with precipitation—an average of 7. During the winter period, especially in January (average temperature 0.4°C, minimum -3.5°C) and February (average temperature 2.6°C, minimum -2.3°C), these minor precipitation events most likely occur as light snow or individual flurries. In December (average temperature 4.1°C, minimum -0.1°C), similar snowfall or sleet is also possible. The number of precipitation days in winter fluctuates between 8 and 10, implying frequent but very sparse snowfall or frost.

When planning a trip to Alton, it is important to consider the weather variability throughout the year to ensure your wardrobe is as comfortable as possible. Regardless of the season, comfortable walking shoes will be your best companion, as the city is perfect for exploring on foot. Given that the total precipitation is low but the number of rainy days can be significant (7 to 13 per month), a light umbrella or compact raincoat will be useful year-round. The principle of layering clothing is the key to comfort, as it allows you to easily adapt to temperature changes throughout the day.

The summer months (June–August) in Alton are warm, with average temperatures around 25–26°C. It is recommended to pack light, breathable clothing made from natural fabrics, sunscreen, a hat, and sunglasses. Evenings can be slightly cooler, so a light sweater or cardigan will come in handy. In spring (March–May) and autumn (September–November), the weather is changeable: temperatures range from cool to moderately warm. During these periods, it's worth taking jeans or trousers, long- and short-sleeved t-shirts, a sweater or fleece, and a mid-season jacket. Precipitation is more likely in spring, so a waterproof jacket will be useful.

In winter (December–February), Alton is chilly, with average temperatures staying around 0–4°C and nighttime lows often dropping below zero. For a winter trip, pack a warm jacket or coat, sweaters, a hat, scarf, and gloves. Although heavy snowfall is not common, warm and waterproof footwear will provide comfort during walks. Don't forget about layering: thermal underwear can be a great addition to your winter wardrobe, especially if you plan to spend a lot of time outdoors.