Lisbon weather by month: official climate normals
A month-by-month Lisbon weather reference built from IPMA's 1991–2020 climate normal — useful for planning, without pretending an average can forecast your week.
Use climate normals for planning, not for predicting your week
The most useful Lisbon weather baseline is the Portuguese weather service IPMA's 1991–2020 climate normal for Lisboa / Instituto Geofísico. A climate normal tells you what is typical over decades; it does not tell you whether your specific Tuesday in April will be sunny.
That sounds obvious, but it fixes a common travel-planning mistake: choosing a month from a generic sunshine icon and then packing as if variability has been cancelled. Lisbon's Atlantic setting can still deliver wind, rain or exceptional heat outside the monthly average.
IPMA — official climate normals
Lisbon month by month: official temperature and rain normals
The table below uses IPMA's 1991–2020 mean daily maximum/minimum temperature, monthly precipitation and average number of days with at least 1 mm of rain. I prefer these official measures to vague “rain days” copied between travel sites.
| Month | Mean high | Mean low | Rainfall | Days ≥1 mm rain |
|---|---|---|---|---|
| January | 15.1°C | 8.6°C | 103.8 mm | 10.0 |
| February | 16.4°C | 9.1°C | 77.8 mm | 7.9 |
| March | 18.9°C | 11.0°C | 68.7 mm | 7.6 |
| April | 20.4°C | 12.3°C | 71.8 mm | 7.9 |
| May | 23.1°C | 14.4°C | 57.8 mm | 5.8 |
| June | 26.1°C | 16.8°C | 14.1 mm | 2.0 |
| July | 28.2°C | 18.2°C | 2.6 mm | 0.6 |
| August | 28.8°C | 18.8°C | 5.4 mm | 1.1 |
| September | 26.6°C | 17.6°C | 38.6 mm | 3.8 |
| October | 22.8°C | 15.3°C | 110.6 mm | 8.7 |
| November | 18.1°C | 11.8°C | 133.9 mm | 9.9 |
| December | 15.4°C | 9.4°C | 108.5 mm | 10.0 |
Annual mean precipitation in this IPMA normal is 793.5 mm. The pattern is the useful part: July and August are exceptionally dry on average; October through January is much wetter.
December to February: mild temperatures, real rain risk
Winter is excellent for museums, food and a flexible city break, but “mild” should not be translated as “dry”. Mean daytime highs sit around 15–16°C, while December and January both average about 10 days with at least 1 mm of rain. Pack a proper light waterproof layer and shoes that grip wet calçada.
The upside is that a winter forecast can still contain bright, pleasant walking windows. I would plan the indoor options first and move viewpoints/neighbourhood walks into the best weather block rather than locking every hour before you arrive.
March to May: the easy walking season
Spring warms steadily from a 18.9°C mean March high to 23.1°C in May. Rain is still a genuine part of March and April, while May is drier on the long-term normal. For a first trip built around Alfama, Belém and long neighbourhood walks, late spring is one of the easiest weather compromises.
Bring layers. A sunny afternoon can feel warm in a sheltered square while a riverfront breeze or evening viewpoint feels much cooler.
June to August: dry, bright and capable of serious heat
June, July and August are dramatically drier in the IPMA normal. The mean high reaches 28.8°C in August, but the climate record also shows that very hot days are not theoretical: IPMA's 1991–2020 statistics include multiple days each summer month above 30°C, and historical extremes far above the monthly mean.
So I do not build a summer Lisbon itinerary around the average high. Put the steepest outdoor walking earlier, carry water, use shade and Metro/CARRIS to remove unnecessary climbs, and keep a heatwave alternative. Beaches can be appealing, but Atlantic water, wind, swell and beach flags need their own live check.
September to November: excellent transition, then wetter fast
September remains warm on the normal — 26.6°C mean high — with far less rain than October or November. That makes it one of the strongest all-round months for people who want city walking plus a possible coast day without peak midsummer dryness/heat.
The change after September is meaningful: average monthly precipitation jumps to 110.6 mm in October and 133.9 mm in November. Autumn can still produce beautiful days, but by late season I want a plan that can switch between neighbourhoods and indoor sights without feeling “ruined”.
What I would pack by season
- Winter: light waterproof shell, layers, grippy shoes, compact umbrella only as a backup to the windproof layer.
- Spring: layers, small rain shell, sun protection and shoes comfortable on cobbles.
- Summer: breathable clothing, hat, sunscreen, refillable water bottle and one light layer for breezy evenings/interiors.
- Autumn: summer gear in September; progressively add rain protection and warmer evening layers into October/November.
When to stop looking at averages
About a week before travel, switch from climate planning to the actual IPMA forecast and warnings. If heat, heavy rain or strong wind is forecast, move the day-trip, viewpoint or long hill walk rather than arguing with the weather because a monthly average looked friendly.
Best use of this page
Use the normals to choose a season and pack sensibly. Use IPMA's live forecast to choose what you actually do each day.
Cheers, Carpe Diem & plan from the climate, then obey the forecast! 🍻⏳🌦️
TATS Man
your averages-are-not-a-promise weather desk
Frequently asked questions
- What is the hottest month in Lisbon?
- August has the highest mean daily maximum in IPMA's 1991–2020 Lisbon normal at 28.8°C, closely followed by July at 28.2°C. Individual heatwaves can be much hotter.
- What is the wettest month in Lisbon?
- November has the highest mean monthly precipitation in the IPMA 1991–2020 normal at 133.9 mm, followed by December, October and January.
- Does it rain much in Lisbon in July?
- July is extremely dry on the long-term normal: 2.6 mm average monthly precipitation and only 0.6 days with at least 1 mm of rain. A live forecast still matters.
- Is September a good month for Lisbon?
- September combines a 26.6°C mean high with much lower normal rainfall than October/November, making it a strong city-and-coast compromise for many travellers.