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World Rainfall Map — Calibrated Annual Precipitation for 1000+ Cities
An interactive world rainfall radar showing calibrated annual precipitation for 1000+ cities across 190+ countries. Bergen tops Europe at 2,250 mm/yr; Cairo bottoms the league at 25 mm/yr. Every number is ERA5 reanalysis corrected against the GPCC rain-gauge network — the same data your national met service uses.
How rainfall is calibrated
Raw ERA5 monthly total precipitation — the European Centre for Medium-Range Weather Forecasts product hosted on the Copernicus Climate Data Store — is the gold-standard global reanalysis, but it has two known biases for relocation use. First, it slightly underestimates convective rain in the tropics. Second, its 0.25° (~25 km) native grid smooths orographic spikes on mountainous coasts: the windward side of a Norwegian fjord can receive 3× the rainfall of the leeward valley 30 km away, and ERA5 averages them. GeoRank corrects both using the GPCC (Global Precipitation Climatology Centre) gauge network of 75,000+ stations as the gridded ground truth, then cross-checks station-by-station against national met services.
The second move — and the one that matters most for the lifestyle question "will it rain when I'm there" — is converting monthly totals into rainy-day frequency. Annual mm tells you the volume of water; it doesn't tell you whether it falls as 200 light drizzles or 20 monsoon dumps. GeoRank uses a Gamma-distributed wet-day model that converts the average daily total into the probability that any given day is wet. The closed-form expression is printed below in mono so you can audit it. Full derivation, fit diagnostics, and the GPCC reference table sit on the methodology page.
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Rainfall — wet-day model
Calibrated
●●●●
Wet-day formulap_rainy[m] = 1 − exp(−mm_day / 2.5)
SourceERA5 monthly tp · 1991–2020
Ground truthGPCC gauge network · 75k+ stations
Grid0.25° native → 0.5° display
Coverage1000+ cities · 190+ countries
Accuracy±12% well-gauged regions
Orographic effects in mountain coastal terrain widen the bound to ±25% — Bergen, the Norwegian fjords, the Hawaiian windward slopes, and the Pacific Northwest are the hardest cells to resolve. Climatology is the 1991–2020 WMO reference period; the snapshot refreshes annually.
Full methodology →
Wettest & driest cities worldwide
These are the wettest and driest cities in the GeoRank dataset, ranked by calibrated annual precipitation. The wet list is dominated by tropical monsoon belts and orographic coasts; the dry list collects subtropical deserts and Mediterranean rain-shadow basins. For the underlying climate-zone picture, see our Climate & Rain reference.
☔ Top 10 wettest cities (annual precipitation, calibrated)
- 1Singapore2,340 mm/yr
- 2Bergen, Norway2,250 mm/yr
- 3Mumbai, India2,200 mm/yr
- 4Kuala Lumpur, Malaysia2,150 mm/yr
- 5Auckland, New Zealand1,720 mm/yr
- 6Hong Kong1,680 mm/yr
- 7Valentia, Ireland1,560 mm/yr
- 8Tokyo, Japan1,500 mm/yr
- 9Manila, Philippines1,450 mm/yr
- 10Bangkok, Thailand1,420 mm/yr
Wet vs dry — head-to-head by annual mm and rainy-day frequency
| City |
Region |
Annual rainfall |
Rainy days/yr |
Notes |
| Singapore | Tropical (SE Asia) | 2,340 mm | ~178 | Year-round convection, no dry season |
| Bergen | Maritime Norway | 2,250 mm | ~220 | Orographic Atlantic seam, 60°N |
| Mumbai | Monsoon India | 2,200 mm | ~80 | Concentrated Jun–Sep monsoon |
| Tokyo | Subtropical Japan | 1,500 mm | ~110 | Tsuyu rainy season + typhoons |
| Lisbon | Mediterranean (Portugal) | 700 mm | ~85 | Wet winters, bone-dry summers · Portugal page |
| London | Maritime UK | 600 mm | ~150 | Drizzle-dominated, no real dry season |
| Madrid | Continental Spain | 430 mm | ~63 | Semi-arid plateau · Spain page |
| Almería | Spain (Andalusia) | 200 mm | ~26 | Driest corner of Western Europe |
| Cairo | Egypt (subtropical desert) | 25 mm | ~6 | Effectively rainless |
How to use the rainfall map
The interactive GeoRank rainfall map renders the calibrated precipitation layer as a global cyan gradient — the darker the swatch, the more annual rain. Click any city pin for annual totals, monthly profile, and rainy-day frequency derived from the wet-day formula above. The rainfall layer composes cleanly onto sunshine, temperature, cost, and tax, which is the real relocation question: not "where's dry" but "where's dry, warm, affordable, and visa-accessible."
01
Open the rainfall layer
Deep-link straight into the cyan layer at
/?layer=rain. The intensity is annual precipitation; click any pin to inspect the monthly profile and rainy-day count.
02
Filter by rainy-day frequency
Use the layer slider to clip to "show me everywhere under 60 rainy days/yr" — that picks out the Mediterranean dry belt, the Australian east coast, and the US Southwest in a single sweep.
03
Stack sunshine, temperature, cost
Rainfall is one of seven calibrated layers. Add the
sunshine map on top to find places that are both dry
and bright, then layer
cost of living for the affordability filter.
04
Pin your home as baseline
Set "home" once and every other pin shows precipitation as a delta from where you live now. A Manchester resident comparing the Algarve sees "−750 mm/yr, −80 rainy days."
Open Compare →
Rainfall & relocation — green, mild, dry, arid
High rainfall is not "bad weather" — it's a different lifestyle. Most relocation flows split along a small number of well-understood archetypes, and the rainfall map is the cleanest way to find your archetype. Wet-maritime climates (Bergen at 2,250 mm/yr, London at 600 mm spread across 150 drizzle days, Galicia, southwest France) suit UK and Irish expats who want a familiar grey-green palette without giving up infrastructure. Mediterranean climates (Lisbon at 700 mm/yr, Barcelona, Athens, Tel Aviv) concentrate rain into the winter and produce six rainless summer months — the relocation sweet spot for northern Europeans tired of year-round damp. See our Portugal page for the Lisbon profile in context.
Semi-arid relocation lanes — Madrid at 430 mm/yr, Phoenix, inland Andalusia — appeal to nomads and retirees who explicitly want dry heat and big skies; the trade-off is summer water stress and increasing wildfire risk. True arid destinations (Cairo at 25 mm/yr, Las Vegas, Almería at 200 mm/yr) sit at the dry end of human-habitable rainfall and are typically chosen for cost or visa reasons rather than climate first. The rainfall layer composed against sunshine, temperature, and cost turns that whole space into a single picture you can scan in a minute. For a deeper data-layer view, see Climate & Rain.
Why GeoRank's rainfall map is different
01
Calibrated against gauges, not raw satellite
Raw ERA5 underestimates convective rain and smooths orographic spikes. We correct it against the GPCC gauge network (75,000+ stations) and cross-check station-by-station against Met Office, AEMET, IPMA, DWD, and JMA records. See the
methodology.
02
Rainy-day frequency, not just totals
The wet-day formula p_rainy[m] = 1 − exp(−mm_day / 2.5) turns volume into frequency. Bergen's 2,250 mm/yr is ~220 wet days; Mumbai's 2,200 mm is only ~80 — the lifestyle is completely different and only the frequency surfaces it.
03
Transparent uncertainty bands
±12% on annual totals for well-gauged regions; ±25% on orographic coastal terrain. Most rainfall sites don't publish a single error bar. We publish the bound per cell and explain why.
04
Rainfall in context, not in isolation
Rain alone doesn't pick a city. The same map shows sunshine, temperature, cost, tax, and safety, with your home as the baseline — every destination is a delta, not an abstract number.
Browse all tools →
Related GeoRank tools & data layers
Frequently asked questions
How accurate is the rainfall data?
±12% on annual totals for well-gauged regions after rain-gauge calibration. Orographic and coastal terrain widens that to ±25% — the windward side of a mountain can receive 3× the precipitation of the leeward side over only 30 km, which ERA5's 0.25° (~25 km) native grid cannot fully resolve. Bergen at 2,250 mm/yr sits exactly on that kind of orographic seam; the inland Norwegian plateau ~150 km east drops below 600 mm/yr. Full bounds in the
methodology.
What's the difference between "rainy days" and annual millimetres?
Annual mm is total water volume; rainy-day frequency is how often it falls. GeoRank converts daily totals to rainy-day probability with a Gamma-distributed wet-day model: p_rainy[m] = 1 − exp(−mm_day / 2.5). Bergen at 2,250 mm/yr translates to roughly 220 rainy days (10 mm/day average); Cairo at 25 mm/yr is maybe 2 rainy days (12 mm each). Frequency matters for lifestyle as much as volume.
Why is Bergen much wetter than nearby Swedish cities?
Atlantic maritime exposure plus orographic lift over the Norwegian coastal mountains. Bergen sits on the windward side at 2,250 mm/yr; Valentia on Ireland's west coast records ~1,560 mm/yr for the same reason. Inland Stockholm, sheltered by the Scandinavian range, drops to ~550 mm/yr. Coastal-mountain microclimates dominate European rainfall — and they're exactly where ERA5 needs the most gauge correction.
Is high rainfall bad for relocation?
No — it depends on your lifestyle. UK and Irish expats often move to maritime climates (
Lisbon at 700 mm/yr, Galicia, southwest France) because the rain feels familiar. Digital nomads and retirees from northern Europe more often seek dry heat (Almería 200 mm/yr, Phoenix). The rainfall layer composes onto cost, tax, and sunshine, so you can hold three preferences at once.
Where does the rainfall data come from?
ERA5 monthly total precipitation (
tp) from the Copernicus Climate Data Store, 1991–2020 climatology, native 0.25° grid aggregated to 0.5° for display. Calibration uses the GPCC (Global Precipitation Climatology Centre) gauge network of 75,000+ stations as the gridded ground truth, plus station-level cross-checks against the Met Office UK, AEMET Spain, IPMA Portugal, DWD Germany, and JMA Japan. Full sourcing on the
methodology page.
Is the rainfall data current for 2026?
The dataset uses the 1991–2020 ERA5 climatology — the current WMO-standard 30-year reference period. Year-to-year precipitation varies by roughly ±15%, so any single recent year may differ from the climatology. We refresh the snapshot annually as new ERA5 monthly fields are released by the Copernicus Climate Data Store.
Find your dry — or your green.
The map combines rainfall, sunshine, temperature, cost, and tax on every pin. Set your home as the baseline and every destination shows up as a delta from where you live now.
About the data: GeoRank calibrates ERA5 monthly total precipitation (Copernicus Climate Data Store, 1991–2020 climatology) against the GPCC (Global Precipitation Climatology Centre) rain-gauge network of 75,000+ stations, then converts to rainy-day frequency with a published Gamma-distributed wet-day model (
p_rainy[m] = 1 − exp(−mm_day / 2.5)). National met services (Met Office UK, AEMET Spain, IPMA Portugal, DWD Germany, JMA Japan) serve as independent station-level cross-references. Orographic coastal terrain widens uncertainty to ±25%; well-gauged plains hold to ±12%. See the
methodology for source-by-source detail.
Sources: ERA5 reanalysis (Copernicus Climate Data Store, EU) · GPCC Global Precipitation Climatology Centre rain-gauge network (DWD, Germany) · national meteorological services (Met Office UK, AEMET Spain, IPMA Portugal, DWD Germany, JMA Japan, NOAA US) · WMO 1991–2020 climatological standard normals. Methodology and accuracy bounds at methodology.