Meteorological wildfire index (simplified WRI) for Aragon, based on live data at Zaragoza. Includes regional zoom map, 7-day evolution and sub-indices of temperature, humidity, wind and rainfall.
Aragon 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.
Aragon is the home of the cierzo: a persistent, very dry northwesterly which in summer combines with temperatures above 35 °C and humidity below 20 % in the Ebro valley. That triad lies behind Aragon’s largest fires. In the Pyrenees and the Teruel stretch of the Iberian System the risk is tied more to dry thunderstorms, with lightning but no appreciable rain.
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 — Aragon averages 35 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 56 days a year and, between June and August, the longest dry run averages 26 consecutive days without appreciable rain. Across those three months about 109 mm fall in total. 65 % of those days fall in summer and 2 % 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 | 0.2 | 2.3 | 9.2 | 20.5 | 18.9 | 4.0 | 0.4 | 0.0 | 0.0 |
| Risk days | 0.0 | 0.0 | 0.6 | 3.0 | 5.6 | 6.1 | 8.9 | 7.7 | 3.0 | 0.4 | 0.0 | 0.0 |
| Rain (mm) | 50 | 41 | 63 | 63 | 50 | 55 | 26 | 28 | 47 | 67 | 64 | 44 |
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 Aragon. 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.
