Humidity in Mallorca averages 72% over the year and reaches 77 to 79% from October to January (AEMET, Palma, 1981–2010). The US Environmental Protection Agency advises keeping indoor humidity below 60%. When a second home stays closed for weeks, moisture builds up in walls and fabrics. Controlled ventilation keeps levels stable, as we explain on our ventilation in Mallorca page.
By the technical team of Greentech Balear · Published 25 February 2026 · Updated 14 October 2026
Why is it so humid in Mallorca?
Mallorca is surrounded by the Mediterranean, and sea air constantly carries moisture inland. Relative humidity also depends on temperature. When air cools, the percentage rises even without extra water. That is why readings peak in winter and at night.
The AEMET record at Palma airport shows the pattern clearly:
| Month | Mean temperature | Relative humidity |
|---|---|---|
| January | 9.5 °C | 79% |
| March | 11.3 °C | 75% |
| May | 17.5 °C | 67% |
| July | 24.8 °C | 62% |
| September | 22.2 °C | 71% |
| October | 18.5 °C | 77% |
| November and December | 13.7 / 10.8 °C | 79% |
| Annual mean | 16.5 °C | 72% |
Source: AEMET, climate normals 1981–2010. On the coast and in valleys, readings can be higher than at the airport.
What happens in a second home that stands empty?
A closed house gets no air exchange. Moisture from walls, floors and fabrics stays inside. When damp air meets a cool outside wall, condensation forms. Mould follows, often behind furniture, in corners and around window reveals.
The World Health Organization links indoor dampness and mould with respiratory symptoms and asthma. The EPA advises drying water-damaged materials within 24 to 48 hours. Owners who spend only a few weeks a year in Mallorca often notice the problem only on arrival.
The warning signs are usually the same: a musty smell, clammy bed linen, misted windows in the morning and dark patches in corners. To prepare the house before you leave, see our guide to preparing a Mallorca second home for winter.
What indoor humidity is right, and how do you reach it?
The EPA recommends keeping indoor humidity below 60%, ideally between 30 and 50%. Spain’s building services regulation (RITE) uses 40 to 50% for winter design and 45 to 60% for summer. A simple hygrometer shows where you stand.
While you are in the house, airing helps. Open windows wide for a few minutes several times a day rather than leaving them tilted. Run the bathroom fan or open a window when showering or cooking, as the EPA advises.
An empty house needs equipment that works without you:
- Measure: a hygrometer with data logging or remote display in the bedroom and bathroom.
- Check: bathroom fans, air paths, filters and condensate drains of existing units.
- Ventilate: mechanical ventilation with heat recovery, controlled by humidity.
- Dehumidify: air conditioning in dry mode or a dehumidifier for problem rooms.
- Monitor: regular on-site checks while you are away.
We plan these steps with you on our ventilation in Mallorca page. For checks while you are away, see our property maintenance and annual check.
What we see in homes across Mallorca
Humidity is a question many owners ask. According to Greentech Balear’s Search Console data (July to October 2026), the German version of this article appeared 1,088 times in Google Search, 839 of them for “Luftfeuchtigkeit Mallorca” and “Mallorca Luftfeuchtigkeit”. The question “why is the humidity in Mallorca so high” in German appeared 104 times.
On our visits, bedrooms, bathrooms and outside walls behind wardrobes are the most common problem areas. We advise moving furniture 3 to 5 cm away from outside walls so air can circulate. Near the coast, salt and moisture put more strain on filters and equipment. There we plan shorter maintenance intervals.
Frequently asked questions
How humid is Mallorca in winter?
At Palma airport, mean relative humidity is 79% from November to January and 77% in October (AEMET, 1981–2010). In summer it falls to 62 to 65%. Right on the coast, readings can be higher. For houses that stand closed, winter is therefore the critical period.
What humidity level is ideal indoors?
The EPA advises keeping indoor humidity below 60%, ideally between 30 and 50%. Spain’s RITE regulation designs for 40 to 50% in winter and 45 to 60% in summer. If your readings stay above 60% for several days, have the cause checked before mould appears.
Does air conditioning help with humidity?
Yes, within limits. When cooling, an air conditioner removes water from the air, and many units have a dry mode. The EPA lists air conditioners and dehumidifiers as moisture control measures. It does not replace air exchange. Keep the drip pan and drain line clean, or they become a source of damp themselves.
Should I leave windows tilted when I leave?
No. Tilted windows cool the wall next to the frame and encourage condensation. They also leave the house open to rain and intruders. Better options are mechanical ventilation, a humidity-controlled dehumidifier or regular checks by a property care service.
When should a professional inspect the house?
Have it checked if humidity stays above 60% for several days or condensation appears most mornings. The same applies to dark stains, flaking paint or a smell that remains after airing. After a leak, the EPA advises drying affected areas within 24 to 48 hours to prevent mould.
Sources
- AEMET — Climate normals, Palma de Mallorca Airport: normals 1981–2010, relative humidity 62 to 79%, annual mean 72%.
- EPA — A Brief Guide to Mold, Moisture and Your Home: indoor humidity below 60% (ideally 30 to 50%), drying within 24 to 48 hours, air conditioning and dehumidifiers.
- WHO — Guidelines for indoor air quality: dampness and mould (2009): dampness and mould as a health risk.
- BOE — Regulation on Thermal Installations in Buildings, RITE (RD 1027/2007): design values of 40 to 50% in winter and 45 to 60% in summer.
Dealing with damp in your Mallorca home? Call us on +34 644 450 672, write to info@greentechbalear.com or visit our ventilation in Mallorca page.
By the technical team of Greentech Balear – energy solutions and building services in Mallorca: solar PV, air conditioning, heat pumps, heating, ventilation and maintenance.