Meteorological wildfire index (simplified WRI) for Canary Islands, based on live data at Santa Cruz de Tenerife. Includes regional zoom map, 7-day evolution and sub-indices of temperature, humidity, wind and rainfall.
Canary Islands 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.
The Canaries have a regime of their own: the big fires occur in the Canary pine belt at mid-altitude when the so-called tiempo sur — very hot, dry Saharan air, humidity below 15 % and temperatures above 35 °C — coincides with strong wind. Canary pine resprouts after fire, but the extreme terrain, with deep ravines and steep slopes, makes spread very fast and suppression very difficult.
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 — the Canary Islands average 7 days a year of fire-prone weather. That is a middling figure, and it almost always arrives as episodes of several consecutive days rather than as isolated ones. The month with most such days is July, followed by August.
The thermometer passes 30 °C on about 21 days a year and, between June and August, the longest dry run averages 60 consecutive days without appreciable rain. Across those three months about 31 mm fall in total. 71 % of those days fall in summer and 3 % 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 | 0.1 | 0.4 | 0.5 | 1.2 | 6.7 | 8.5 | 2.0 | 1.7 | 0.0 | 0.0 |
| Risk days | 0.0 | 0.1 | 0.1 | 0.3 | 0.6 | 1.1 | 2.2 | 1.7 | 0.5 | 0.0 | 0.0 | 0.0 |
| Rain (mm) | 35 | 51 | 39 | 31 | 16 | 14 | 2 | 15 | 34 | 42 | 45 | 41 |
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 the Canary Islands. 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.
