Practical guide · Lisbon
Lisbon weather by monthtemperature, rain and sea
Lisbon's 1991–2020 climate normals month by month: daytime highs from 15 °C in January to 29 °C in August, about 10 rain days a month in winter and almost none in July, and a sea of 15–20 °C off Cascais and Ericeira.
- January: high 15.1 °C, low 8.6 °C, 10 rainy days, sea 15.7 °C
- February: high 16.4 °C, low 9.1 °C, 7.9 rainy days, sea 15.2 °C
- March: high 18.9 °C, low 11 °C, 7.6 rainy days, sea 15 °C
- April: high 20.4 °C, low 12.3 °C, 7.9 rainy days, sea 16.2 °C
- May: high 23.1 °C, low 14.4 °C, 5.8 rainy days, sea 17.3 °C. One of the best months.
- June: high 26.1 °C, low 16.8 °C, 2 rainy days, sea 18.6 °C. One of the best months.
- July: high 28.2 °C, low 18.2 °C, 0.6 rainy days, sea 18.9 °C
- August: high 28.8 °C, low 18.8 °C, 1.1 rainy days, sea 19.6 °C
- September: high 26.6 °C, low 17.6 °C, 3.8 rainy days, sea 19.9 °C. One of the best months.
- October: high 22.8 °C, low 15.3 °C, 8.7 rainy days, sea 19.8 °C. One of the best months.
- November: high 18.1 °C, low 11.8 °C, 9.9 rainy days, sea 18.1 °C
- December: high 15.4 °C, low 9.4 °C, 10 rainy days, sea 16.5 °C
Long-term averages, not a forecast. Source: IPMA: Normal Climatológica 1991–2020, Lisboa / Instituto Geofísico (station 535, 9.1497W, 77 m), read .
Short answer: Lisbon is mild all year. Highs run from 15 °C in January to 29 °C in August; rain falls mostly October to January (8–10 rain days a month) and almost never in July. The sea off Cascais and Ericeira stays between 15 and 20 °C. Which months suit which trip: best time to visit Lisbon and the coast.
| Month | High °C | Low °C | Rain mm | Rain days | Sea °C |
|---|---|---|---|---|---|
| January | 15.1 | 8.6 | 103.8 | 10.0 | 15.7 |
| February | 16.4 | 9.1 | 77.8 | 7.9 | 15.2 |
| March | 18.9 | 11.0 | 68.7 | 7.6 | 15.0 |
| April | 20.4 | 12.3 | 71.8 | 7.9 | 16.2 |
| May | 23.1 | 14.4 | 57.8 | 5.8 | 17.3 |
| June | 26.1 | 16.8 | 14.1 | 2.0 | 18.6 |
| July | 28.2 | 18.2 | 2.6 | 0.6 | 18.9 |
| August | 28.8 | 18.8 | 5.4 | 1.1 | 19.6 |
| September | 26.6 | 17.6 | 38.6 | 3.8 | 19.9 |
| October | 22.8 | 15.3 | 110.6 | 8.7 | 19.8 |
| November | 18.1 | 11.8 | 133.9 | 9.9 | 18.1 |
| December | 15.4 | 9.4 | 108.5 | 10.0 | 16.5 |
High, low, rain and rain days (≥ 1 mm): IPMA climate normal 1991–2020 for Lisboa / Instituto Geofísico, a station at 77 m in the city. Annual total 793.5 mm over 75.5 rain days; 110.6 days a year reach 25 °C and 33.2 days reach 30 °C. Sea: seatemperature.org monthly averages for Cascais (modelled).
Lisbon in winter
Mild but wet. From December to February, daytime highs average 15.1–16.4 °C and nights 8.6–9.4 °C. December and January each bring about 10 rain days and over 100 mm of rain; February is drier, with about 8. Frost is essentially absent at the city station. [IPMA]
- Sea: about 15–16.5 °C off Cascais (modelled), so the beaches are for walks and surfers in wetsuits, not swimming. [seatemperature.org]
- What changes: shorter opening hours at some sights, for example the São Jorge castle is open 9:00–18:00 from November to February (last admission 17:30) and closed all day on 24, 25 and 31 December and 1 January. [castelodesaojorge.pt, 10 Oct 2026]
- Christmas: in 2025 the city’s lights in Terreiro do Paço came on every evening from 22 November to 6 January; we found no 2026 dates on the city’s website on 10 October 2026. [informacao.lisboa.pt] Christmas markets, New Year’s Eve, the 1, 8 and 25 December holidays and what closes: Lisbon in December. Rainy-day plans: things to do in Lisbon.
- With kids: plan one indoor anchor per day (the Oceanário and the science centre sit side by side); the full list is in Lisbon with kids.
- For a work month: which months suit which trip is on best time to visit Lisbon.
Heat and extremes
- Days with a maximum of 30 °C or more: 5.7 in June, 8.5 in July, 10.2 in August, 5.7 in September. [IPMA]
- The station’s record high in the period is 43.3 °C (4 August 2018). [IPMA]
- The coast is usually cooler and windier than the city; this page has no coastal station.
- Heat warnings, the June festivities and beaches without a car: Lisbon in summer. September to November, with the return of the rain: Lisbon in autumn.
Source references
- IPMA: Normal Climatológica 1991–2020, Lisboa / Instituto Geofísico (station 535, 9.1497W, 77 m) · accessed
- seatemperature.org: Cascais monthly average sea temperature (modelled; same values shown for Ericeira) · accessed
- Informação Lisboa: Lisboa celebra o início do Natal (23 Nov 2025: lights in Terreiro do Paço from Saturday 22 Nov, daily from 17:30 until 6 Jan) · accessed
- Castelo de São Jorge: Schedules (winter Nov–Feb 9:00–18:00, last admission 17:30; closed 24, 25, 31 Dec and 1 Jan) · accessed
Quick answers
What is the warmest month in Lisbon?
August, with a mean daily maximum of 28.8 °C and a mean minimum of 18.8 °C (IPMA normal 1991–2020, Lisboa / Instituto Geofísico).
What is the coldest month in Lisbon?
January: mean daily maximum 15.1 °C and minimum 8.6 °C. Frost is essentially absent; the station records 0.0 days a year with a minimum below 0 °C.
How warm is the sea near Lisbon?
Around Cascais and Ericeira the monthly average runs from about 15.0 °C in March to 19.9 °C in September (seatemperature.org, modelled).
Is Lisbon worth visiting in December?
Yes, if you plan for rain. December averages highs of 15.4 °C and lows of 9.4 °C with about 10 rain days (IPMA 1991–2020), so it is mild but wet. Keep one indoor plan per day, such as the Oceanário or the Gulbenkian. The city's Christmas lights ran from 22 November 2025 to 6 January 2026; 2026 dates were not announced on 11 October 2026. Markets, New Year's Eve and holiday closures: our Lisbon in December guide.
What is the weather like in Lisbon in winter?
Mild and wet: December to February highs of 15–16 °C and lows of 8.6–9.4 °C, with 8–10 rain days a month and frost essentially absent (IPMA 1991–2020, Lisboa / Instituto Geofísico). The sea off Cascais is about 15–16.5 °C.