Last and first frost dates in Castelo Branco

When is the last frost in Castelo Branco?

The last frost in Castelo Branco usually comes around 17 January: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 27 December, while corn waits until 17 February. The first autumn frost follows around 26 December, about 343 days later: harvest or cover frost-tender crops before then.

When to sow and plant

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

When the soil warms up in Castelo Branco

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 4 days before the last spring frost and 15 °C 75 days after it.

Frost dates near Castelo Branco

Of the nearest cities on our list, the last spring frost ends earliest in Cáceres (21 January) and latest in Guarda (2 April).

Seeds, seedlings and markets in Castelo Branco

Within 15 km of Castelo Branco OpenStreetMap lists 1 garden centre, 2 farm-supply shops and 2 markets (collected 27 October 2026). The nearest farm supply to the city centre is Agriloja, 4 km away.

• Agriloja — farm supply
  Rua R LT 32, 6000-790 Castelo Branco · Mon–Sat 08:30–20:00; Sun 09:00–13:00 · 4 km · agriloja.pt

• Where to buy seeds and seedlings in Castelo Branco
• Selling your own harvest in Portugal

Places: © OpenStreetMap contributors, ODbL.

Weather in Castelo Branco by month

Average weather in Castelo Branco over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: April–October (21–35.1 °C). Months that average 30 °C or more by day: July (34.6 °C) and August (35.1 °C). No month averages below 0 °C at night; the coldest nights, in January, average 5 °C. About 695 mm of rain falls in a year, on 85 days; November is the wettest month (103 mm) and August the driest (2 mm).

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).