The 2026 La Vuelta a España is complete (raced 22 August – 13 September 2026), so this edition is built entirely from observed data — every stage-day condition and every 50-year baseline value comes from the same source, Open-Meteo's Copernicus ERA5 reanalysis archive (1940–present). There is no forecast/"today" path for this edition — every card ships in its final, permanent state.
Stage 3 (Gruissan-Aude → Font Romeu) was cancelled mid-race after a hailstorm and never raced — it shows no observed or forecast conditions at all, deliberately, rather than a plausible-looking number for a route nobody rode. Stage 15 was shortened mid-race under La Vuelta's Extreme Weather Protocol for forecast extreme heat; the conditions shown are for the route actually raced.
Route facts (towns, distances, climbs, dates) are drawn from lavuelta.es's published stage information and the race's official roadbook, cross-checked against ProCyclingStats — never Wikipedia, and never by tracing a graphic (see the elevation section below).
Stage times are computed in race-local time — Europe/Paris for stages 1–3 (Monaco/ France), Europe/Andorra for stage 4, Europe/Madrid for stages 5–21 (Spain).
This site uses aggregate, cookieless visitor analytics via Vercel — no personal data is collected, and there's no third-party tracking.
We estimate Wet Bulb Globe Temperature using the Minard (1961) combination — WBGT = 0.7·Tnwb + 0.2·Tg + 0.1·Ta — the same combination used by Cvijanovic et al. (2026, via ECMWF's thermofeel library). Our natural-wet-bulb and black-globe sub-terms are a documented simplification, not a full port of the iterative Liljegren et al. (2008) model, so treat WBGT values as estimates, not certified measurements. WBGT is always shown in °C — it's a regulatory index (the UCI High Temperature Protocol publishes its thresholds in °C), so it doesn't convert with the °C/°F toggle.
For each stage's finish town (and mountain-pass sample points, where relevant), we pull ERA5 daily maximum temperature for every year 1974–2023, within ±7 days of the stage's calendar date — late-August to mid-September windows here, reflecting La Vuelta's later place in the season compared to the July Tour de France. The anomaly shown on every stage card is the observed max minus that 50-year mean, at the same location, from the same source — never mixed across sources or points. Decade means and the "then vs now" day-count comparison are drawn from the same 50-year window.
Across the 20 stages that raced, finish-town anomalies averaged +2.9°C against the 50-year baseline, ranging from −1.5°C to +9.1°C — mostly positive, but not uniformly so (three stages read at or below their baseline). Stage 15's +7.0°C reading lines up with the fact that La Vuelta's own Extreme Weather Protocol was invoked that day for forecast extreme heat, an independent real-world confirmation rather than an artifact of how we compute the number.
We checked the pipeline itself directly rather than assume it's sound: running the identical baseline + observed methodology against the same calendar dates in 2021 and 2024, at real stage finish locations, produced anomalies scattered near zero and mixed in sign — not the mostly-positive pattern seen throughout 2026. Same code, same 50-year baseline, only the year changes.
Each stage page shows a decade-by-decade mean (the "warming stripes") built from the same narrow ±7-day window used for the baseline — about 150 daily-max readings per decade, at one specific point. A handful of the later stages (16–20, running along the Atlantic-facing Huelva/Cádiz coast and the Granada high country in early-to-mid September) show a flat or even slightly negative trend across the 50 years, in contrast to the clear warming most other stages show.
We checked this wasn't a computation error by reproducing it independently from the raw archive, then re-ran it against a much larger sample — the full June–September window, roughly 1,200 days per decade instead of 150 — for one of the flattest cases (Stage 16's finish, La Rábida, Huelva). The same pattern held: a peak in the 2004–2013 decade, then a decline in 2014–2023 back near the 1974–1983 level. So this isn't sampling noise from a short window — it's a genuine feature of this specific location in the ERA5 record.
It doesn't contradict the broader picture that Southern Spain has warmed. A 50-year trend at one point is not the same measurement as a regional or seasonal climate summary, and the two can legitimately disagree. Coastal Atlantic-facing stretches of Iberia (exactly where stages 16–18 run) have a documented pattern of intensifying coastal upwelling in recent decades, which can locally mute or reverse a warming trend even while the wider region and inland areas continue to warm. Trend strength also isn't uniform across the calendar — this site's own numbers show a much stronger 50-year trend for the August stages than the early-September ones. Treat any single stage's decade trend as a local, one-point reading, not a substitute for a full regional climate assessment.
Stage 12 finished on Calar Alto's summit (2,140 m) — this edition's high point. ERA5's grid cell (~28 km) smooths an isolated peak like this heavily, so the finish-point absolute temperature reads somewhere between true summit and true valley conditions, not a precise on-summit reading. The anomaly is still valid (the same grid-cell offset applies to both the observed value and the 50-year baseline, so it cancels out) — but for the raw heat story on this stage, the route-max line (lower down, before the final climb) is the more physically meaningful number.
Elevation comes from the Open-Meteo Elevation API, itself based on the Copernicus DEM 2021 release GLO-90 (90m resolution), available worldwide under a free license (attribution: the Copernicus program, via doi.org/10.5270/ESA-c5d3d65, and Open-Meteo). We sample ~200 points per stage along the route and cache the result as static data — it's a one-time fetch, since real terrain never changes.
The route between waypoints is a straight-line (geodesic) approximation, not the actual road: no openly-licensed, key-free, production-permitted routing API was available. A single long chord between two sparse points can cut across terrain the road never touches, so every stage was densified with real intermediate towns from the official roadbook and lavuelta.es's published stage descriptions (names, order, and confirmed elevations — read as text/figures, never traced from a profile graphic).
A validation pass flags any stage with a long run of identical elevation samples (a sign of a chord crossing open water) and cross-references each stage's cached maximum against every known climb/col elevation on record, flagging anything more than 150m over. Seven stages (1, 4, 8, 12, 13, 18, 20) had a flagged stretch replaced with a direct taper between two confirmed elevation points instead of left as a terrain-sampling artifact. Six more (2, 3, 10, 16, 17, 21) were individually reviewed against official sources and kept as genuine mountainous or hilly terrain, not an error — the largest remaining gap is stage 16, where the cached path peaks around 220m above the nearest confirmed point (real Sierra de Aracena terrain, with no closer official elevation to verify against).
Elevation resolution and weather resolution are different things.The band's shape comes from ~200 real elevation samples; its color comes from only the handful of points we have actual weather for (start/mid/col/finish and any climb over 1,000m), interpolated between them along the route.
Vertical scaleis proportional to each stage's real relief against a reference computed fresh from this edition's own cached elevation data — the largest real relief of any Vuelta stage, not shared with another edition's scale, so heights are never mixed across races.
Fill color comes from the same temperature ramp used everywhere on this site, anchored to 10–42°C — the plausible range for European summer racing.
Methodology inspired by Cvijanovic, I., Begg, J.D., Mistry, M.N., Petrova, D., Brimicombe, C., Sultan, B. (2026). "The future of European outdoor summer sports through the lens of 50 years of the Tour de France." Scientific Reports, 16, 2644.
UCI High Temperature Protocol thresholds: uci.org.
This site is built by FrontRunners, a charity working to protect the future of sport. FrontRunners helps athletes, teams and sporting bodies understand and respond to the ways climate change is, and will, affect sport from the grassroots to the elite level. This site is an independent project, not affiliated with La Vuelta a España, ASO, Unipublic, or the UCI. Corrections and questions: info@frontrunners.org.au.
This site was developed using Claude (Anthropic's AI model) for code, research, and data-pipeline work, under human direction and review. Every computed number passed a human-verified audit: baselines validated against published climate normals, observed temperatures checked against reported conditions, and every displayed figure required to reconcile arithmetically on the page. No photography and no AI-generated imagery appear anywhere on this site — every visual element (charts, elevation bands) is generated directly from the underlying data. The full methodology, data sources, and known limitations are published on this page.