How the climate of an area affects a home

When looking for a home, you may treat the climate as a matter of personal preference: whether you prefer hot or cold weather, sunshine or rain. But there is another way to assess a location's climate that has little to do with comfort and a great deal to do with money: how the weather affects the property itself.

Persistent rain is more than just inconvenient. Frost does more than make it harder to leave the house in the morning. Wind does more than make a terrace unpleasant. Each of these weather conditions has a cumulative effect on materials, systems and building components. This directly affects maintenance, repairs and the cost of owning the property over time.

What we analyse and how

Hogarfax shows five climate variables for each location: heavy rainfall, summer heat, frost, relative humidity and strong winds. The data comes from the nearest AEMET weather station and reflects historical averages for the past five years.

We should be clear about one point: these figures are indicative. Ideally, sensors on the plot itself would measure the exact conditions at each location. We do not have that capability. The nearest AEMET station may be several kilometres away, and the local microclimate - affected by the slope's orientation, nearby bodies of water and altitude - may differ from the station's readings. We always make this clear because we believe it is important that you know.

That said, historical averages from the nearest station are the best estimate available to any buyer, and they are the same data used by technical professionals, insurers and designers when assessing the climate conditions in an area.

Why each variable matters to a home

Heavy rainfall - measures the number of days per year with at least 10 mm of rain. Heavy rain puts roofs, window and door seals, and junctions between materials under pressure. These are the points where leaks develop. In areas with frequent heavy rainfall, keeping the building watertight requires more maintenance, and resale properties are more likely to have accumulated water-related defects.

Summer heat - days with a maximum temperature of at least 35°C. Extreme heat causes materials to expand and contract, degrades waterproofing membranes on flat roofs and determines how much it will cost to cool the property in summer. In areas of intense heat, the building's orientation and the quality of its insulation cease to be minor details: they can make a difference of hundreds of euros a year in electricity costs.

Frost - days with a minimum temperature of 0°C or below. Water expands when it freezes and can burst external or poorly protected pipes. Over the years, the same freeze-thaw cycle cracks stone, mortar and porous finishes. In resale properties located in areas with frequent frost, the external plumbing deserves a specific inspection before you buy.

Relative humidity - the annual average. High humidity encourages condensation on thermal bridges and cold surfaces, eventually causing staining and mould. In poorly insulated or inadequately ventilated buildings, condensation can also form within the building envelope itself, damaging insulation or rotting timber components without being visible from inside.

Strong winds - days with gusts of at least 55 km/h. A viewing on a calm day tells you nothing about how the house performs when the wind blows. In areas with many days of strong winds, loose roof tiles, poor-quality windows and doors, aerials and inadequately secured roof elements are the first to suffer. On terraces and in gardens, frequent strong winds affect what you can place outside and how it must be anchored.

What Hogarfax can and cannot tell you

We give you a historical picture of the area's climate, put into context against the rest of Spain, together with the reference AEMET station and its distance from the property. It is a starting point for asking the right questions before a viewing: does this house have a flat roof in an area prone to frost? Is there damp in the corners? Do the windows and doors appear to be properly sealed?

What we cannot give you - yet - is an exact measurement for the plot. We wish we could. In the meantime, AEMET's historical data is the best tool available to any buyer who wants to attend a viewing armed with more information than the property listing provides.