- How much has Italy warmed since 1940?
- Comparing the 1991–2020 climate normal with the 1961–1990 one, the cities monitored by this site show an average warming of +1.0°C. That's the same method — the difference between two 30-year averages — used identically across every page of the site.
- What data does Italia Rovente use?
- The ERA5 reanalysis by ECMWF/Copernicus (C3S), distributed by Open-Meteo: air temperature at 2 meters above ground since 1940, updated automatically every day.
- How many cities does the site cover?
- 107 Italian cities, from the main ones (with precise max/min data) to provincial capitals. Full list at italiarovente.app/en/citta.
- Why do the 12 main cities show two slightly different warming numbers?
- On the 12 main cities we show a second comparison, computed with the same method (1991–2020 normal minus 1961–1990 normal) but on an independent source: E-OBS, built by the ECA&D/Copernicus project solely from direct European weather-station observations, not from a model like ERA5. The two sources use different methods, resolutions, and station networks, so a difference of a few tenths of a degree between the two numbers is normal, not an error — what matters is that neither contradicts the other on the direction of warming. E-OBS data: EU-FP6 project UERRA and the Copernicus Climate Change Service, provided by the ECA&D network (ecad.eu); source: Cornes et al. 2018, An Ensemble Version of the E-OBS Temperature and Precipitation Datasets. Non-commercial use, per the E-OBS license.
- Is this an official weather service?
- No. It is informational and educational: it does not replace official weather services or ISPRA data, and should not be used for critical decisions (safety, agriculture, navigation).
- How is a city's warming calculated?
- As the difference between the 1991–2020 climate normal and the 1961–1990 one (the WMO reference period): a comparison between two 30-year averages, not between a recent year and the past, because it's the most robust and least noisy measure.
- Can I cite the data from this site?
- Yes, with attribution to Italia Rovente and the data source (Open-Meteo / ERA5 / ECMWF-Copernicus). The site's code is open source under the MIT license.
- Why doesn't the site cover ice ages or much older climate?
- Because we use direct instrumental data (the ERA5 reanalysis), reliable only from 1940 onward. Older periods require paleoclimatology, which reconstructs climate through indirect proxies — ice cores, tree rings, sediments — with uncertainty that grows the further back in time you go. A different method, same principle: science is built on verifiable facts and data. Everything else — alarmism or minimization — is narrative, and we don't show any of it here.
- Which Italian cities have the most extreme summer heat days ("African heat")?
- The up-to-date ranking is at italiarovente.app/en/classifiche, "The most scorching days" section: days with a high ≥30°, averaged over the last 5 full years for each monitored city, refreshed automatically — we don't quote a fixed number here because it would change and quickly go stale.