Meteo Francoforte sul Meno in aprile

Regulars are specific that daytime highs typically don't climb much past 25C, and that this month still runs cold enough that closed shoes beat sandals even on a decent day, with a forecast capable of swinging from a sunny 15-17C to genuinely cold and rainy within the same week. Our row backs that mild, still-showery read, 21.1C over 10.4C nights, with 68.4mm of rain across 9.2 days and humidity at 68 percent. Regulars are consistent air conditioning is a non-issue this early, a light jacket or sweater covering most days rather than a heavier coat. Checking the forecast close to a trip's dates beats relying on any single seasonal average. The record: 11.2 hours of sun, a 14.6 kph wind and AQI 51.

Locals are candid about how far ahead a forecast here can actually be trusted: not reliable beyond about three days out, and even then an afternoon thunderstorm can build from nothing. Our row backs the warm, humid read they describe along the Rhine - 27C reading as 27C at 64.6 percent humidity, over 16.1C nights - with 54.3mm of rain across 7.9 days, consistent with the afternoon-storm pattern rather than steady rain. Their standing packing advice is layers regardless of the daytime forecast: a light rain jacket and a sweater for evenings that cool down more than the day suggests they will. The record: 10.8 hours of sun, a 13.5 kph wind and AQI 54.

The question regulars keep answering about July here is about the room rather than the street: mid-July can reach 30 to 35C in the Upper Rhine plain, and most apartments and short-lets have no air conditioning, so it is worth checking before booking. Our row's average is milder at 26.9C over 16.1C with 62 percent humidity - the figures they quote are the top of the range. They also warn that summer weather is changeable and that forecasts hold for about three days, with thunderstorms building from nothing. Evenings belong to the apple-wine gardens of Sachsenhausen rather than to beer gardens. The record: 55.2mm across 8.1 days, 11.9 hours of sun and AQI 50.

September in Frankfurt covers a lot of ground: regulars give a range from 10C to over 25C across the month, with sunny days reaching about 20C and nights much cooler, and rain turning up roughly half the time and not always warm rain. Our row lands in the middle at 22.6C days and 12.4C nights with 7 precipitation days. One traveller's account is the shape of a typical visit - three hot but dry days at the start, then chilly mornings, comfortable mid-afternoons, chilly evenings and a couple of days of cloud and intermittent showers. The packing answer is layers plus real rain protection, shoes included, with long trousers and a light sweater as the base. The record: 61.1mm of rain, 8.8 hours of sun and humidity 70 percent.