Meteorological wildfire index (simplified WRI) for Castile and Leon, based on live data at Valladolid. Includes regional zoom map, 7-day evolution and sub-indices of temperature, humidity, wind and rainfall.
Castile and Leon operates a regional wildfire emergency plan coordinated with the Spanish Directorate-General for Civil Protection. During the official high-danger season, stubble burning, bonfires and spark-producing machinery in woodland and the perimeter strip are banned by default.
See also the national overview with the FWI of all 17 Spanish autonomous communities.
Castile and León has more forest area than any other Spanish region and has seen some of the country’s largest fires. The critical pattern is a heatwave with a southwesterly over the sierras of Zamora, León and Salamanca, with continuous scrub and pine on slopes. Rural depopulation has increased the continuity of the fuel as grazing and edge cultivation have disappeared.
Three variables govern the rest: heat, low humidity and wind. Combined into a single indicator — atmospheric evaporative demand (reference ET0) above 4.5 mm a day, maximum gusts over 20 km/h and not a drop of rain — Castile and León averages 36 days a year of fire-prone weather. That is one of the high figures in the country, and it explains why the danger season is declared early here and runs for months. The month with most such days is July, followed by August.
The thermometer passes 30 °C on about 43 days a year and, between June and August, the longest dry run averages 30 consecutive days without appreciable rain. Across those three months about 72 mm fall in total. 76 % of those days fall in summer and 1 % between December and March, a split that says a good deal about which kind of fire is normal here.
| Monthly mean | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days ≥ 30 °C | 0.0 | 0.0 | 0.0 | 0.0 | 1.1 | 6.4 | 17.6 | 16.2 | 1.9 | 0.2 | 0.0 | 0.0 |
| Risk days | 0.0 | 0.0 | 0.3 | 1.6 | 4.4 | 5.6 | 12.0 | 9.6 | 2.2 | 0.1 | 0.0 | 0.0 |
| Rain (mm) | 46 | 40 | 51 | 58 | 41 | 47 | 12 | 12 | 29 | 62 | 55 | 43 |
Meteorology explains when a place can burn, not why it does. In Spain more than nine in ten wildfires are of human origin, between deliberate ignitions and negligence — agricultural burns that escape, machinery throwing sparks, campfires badly put out — and only a minority are caused by lightning. Nor do these figures cover the state of the fuel: two summers with identical heat behave very differently depending on how much rain fell in spring, because a wet spring grows grasses that later dry out and act as a fuse. The indicator also needs reading with one caution: being built on heat and dryness of the air, it captures the summer fire well and falls short on winter episodes of dry mountain wind, which on the Cantabrian coast and in the northwest burn with the thermometer at modest values.
The indicator above is meteorological: it combines temperature, relative humidity, wind and rainfall accumulated over the last 72 hours forecast for the reference point in Castile and León. It does not incorporate the real state of the vegetation or the drought history, and so it does not replace the official index each autonomous community publishes, nor the prohibitions in force during high-danger periods. Faced with a column of smoke, the number that matters is 112.
