Determining the onset of meteorological autumn in Ukraine is a complex and multifaceted process that requires careful analysis of numerous meteorological factors. Contrary to popular belief, the transition to the autumn season is not fixed by isolated temperature readings, but based on long-term and stable observations by specialized experts.

Methodology for Recording the Autumn Season

As explained by Natalia Pтуха, Head of the Media Interaction Department at the Ukrainian Hydrometeorological Center, officially declaring the arrival of meteorological autumn requires the average daily air temperature to drop below +15 degrees Celsius and remain at this level for several consecutive days. A key condition is the presence of a stable trend toward further cooling, ruling out sudden returns of summer heat. If a temporary temperature drop is offset by a subsequent significant warming, the official countdown of the season does not begin.

Current Situation in October 2026

As of early October 2026, temperature readings at many meteorological stations already show values below the critical mark. Specifically, in Kyiv, the average daily air temperature dropped to +12.8 degrees. However, despite local cold snaps and night frosts recorded in various regions, the UkrHMC is still refraining from officially declaring the widespread onset of meteorological autumn, as temperature backgrounds in certain areas are still balancing near boundary values.

Contradictory Data

Confusion often arises in expert circles and the information field between calendar, phenological, and meteorological autumn. While citizens focus on the calendar start of September and the actual appearance of night frosts in early October, official meteorological services approach the issue strictly mathematically. The discrepancy between instantaneous thermometer readings and averaged multi-day data creates a time lag, causing the actual season change to lag behind residents' subjective feelings.

Expectations and Prospects

UkrHMC specialists continue to monitor the synoptic situation, noting that the country is in a transitional period. In the coming weeks, it will become finally clear how stable the current cooling will prove to be and whether regions can firmly establish themselves in the autumn temperature regime without returning to climatic surprises in the form of abnormal warmth.