The State Meteorological Agency (AEMET) has issued September’s first weather alert for the Comunitat Valenciana, covering the northern interior of Castellón. A yellow warning will be in effect from 14:00 to 21:59 on Wednesday because of the risk of intense storms and heavy rainfall, with hail and impressive lightning activity also possible. Up to 20 litres of rain per square metre could fall in just one hour. The chance of these conditions developing is 40% to 70%.
The warning covers the northern interior of Castellón province, where storms are expected to develop during the afternoon. AEMET says they could be locally severe, with intense downpours and hail, as well as frequent lightning in some areas. Nearby towns may see only light rain or remain dry. The agency stresses that the 20-litre threshold is a local maximum, not a forecast for the whole province.
Rain and storm alerts will be active at the same time. The yellow level is considered low risk in the Meteoalerta system, but signals the possibility of weather that could disrupt outdoor activities or travel, or affect vulnerable locations. AEMET advises residents and visitors to watch the sky and check official updates, particularly if they plan to lead, work outdoors or visit mountainous areas during the warning period. Visibility could suddenly drop, and water may accumulate on roads. Hail and brief gusts of wind are also possible, though no specific wind alert is currently in place.
The rest of the Comunitat Valenciana is not covered by the alert for this day, though isolated showers or storms could still occur beyond the designated zone. The warning identifies where the chance of exceeding adverse weather thresholds is highest; it does not show where all rain will fall. AEMET will update its alert map as conditions change and recommends checking for the latest information throughout the day.
The alert comes at the start of meteorological autumn, which began on 1 September, while temperatures remain high for the season in many parts of the region. Warm, humid air at the surface and unstable atmospheric conditions are raising the risk of short but intense storms with frequent lightning. The Mediterranean coast also faces a greater chance of above-average rainfall in the coming months. AEMET estimates a 70% chance that September, October and November will be warmer than usual in eastern Spain, alongside an increased chance of heavy rain, as noted in its outlook for a warmer, wetter autumn in the Comunitat Valenciana.
During storms, AEMET recommends staying out of open areas and away from isolated trees, ridges and elevated points. People should also keep clear of metal structures and suspend outdoor activities if they hear thunder. Drivers should reduce speed and increase their following distance, and avoid crossing flooded areas: even shallow water can conceal road damage or strong currents. The forecast and alerts may change as the situation develops. Up-to-date information is available on AEMET's official weather alert map.
In recent years, weather-related risks in the region have drawn greater attention, particularly after major incidents such as wildfires and severe storms. The Generalitat, for example, has introduced new measures to support forest conservation following wildfire damage, as detailed in this report on compensation for landowners maintaining forest areas. These initiatives form part of wider efforts to adapt to changing weather patterns and limit the impact of extreme events in the Comunitat Valenciana.
