Norderney in May: May is the sunniest spring month with pleasantly warm temperatures, abundant sunshine, and the year's most spectacular blossom displays. Norderney is the second-largest East Frisian island and Germany's oldest North Sea spa. Climate change is leaving visible traces here too: deviations from the long-term mean reveal how weather extremes in Norderney have shifted over the past decades.
May in Norderney typically shows abundant sunshine and warm spring temperatures. Deviations from the 10-year average reveal how the local climate is changing.
Planning around May in Norderney? This page shows the average weather in Norderney during May 2026, compared against the 10-year climatological mean. The comparison covers daily maximum and minimum temperature, sunshine hours, precipitation, and peak wind speed. Those five variables most reliably describe whether a month felt warmer, sunnier, wetter or windier than usual.
Historical weather data for Norderney comes from the ERA5 reanalysis product, a high-resolution dataset maintained by the European Centre for Medium-Range Weather Forecasts (ECMWF) and delivered through Open-Meteo. ERA5 is one of the most accurate publicly available sources for historical Norderney climate values, updated daily and covering every month from 1940 to today. That means typical Norderney May conditions are grounded in measured values, not a statistical model.
The KPI cards on this page each show two numbers: the current May 2026 value for Norderney, and its deviation from the 10-year reference mean. A positive deviation means the month ran warmer, sunnier, wetter or windier than the recent climate normal for Norderney in May. Weather in Norderney Mayhas shifted measurably over recent decades; to explore Norderney May climate year by year, open the climate trend page. To compare Norderney weather against another city for the same month, use the weather comparison tool.
This page is a retrospective, not a forecast. If you are planning travel, a garden project, a photo shoot, or an event in Norderney in May, use the measured historical values as a realistic baseline and treat them as a distribution, not a guarantee. The 10-year mean smooths over individual extreme years; the current-year values show where this particular May sat against that baseline. For typical Norderney May conditions across a longer window, the climate trend page covers every year back to 1940. For day-level detail rather than monthly aggregates, compare arbitrary date ranges for Norderney using the period comparison tool on the homepage.
This page compares the daily measured values of the current year against the average of the last ten years, the so-called 10-year mean. The deviation values in the KPI cards show directly whether the current month is warmer, sunnier, wetter, or windier than usual. The reference data comes from Open-Meteo's ERA5 weather archive and includes daily measured maximum and minimum temperatures, sunshine hours, precipitation totals, and wind speeds.
A ten-year average is short enough to reflect current climate trends, yet long enough to statistically balance out individual extreme years. The World Meteorological Organization (WMO) recommends 30-year normals as the official climate reference, our 10-year mean is deliberately more present-focused and therefore shows the climate change of the most recent decade more clearly.
The daily data for the current year comes directly from Open-Meteo in real time. The reference mean is calculated from actual measured values of the last 10 years, no statistical model, but real historical archive data. The basis is ECMWF's ERA5 reanalysis dataset.
The deviation shows the difference between the current monthly average and the 10-year reference value for the same month. A value of +2.3 °C means: the current month is on average 2.3 degrees warmer than the average of the last 10 years.
Weather review pages are available for over 100 cities in Germany, Austria, and Switzerland. Choose your city from the overview page or use the weather comparison tool on the homepage for custom periods.