According to the AEMET, the month of July 2026 was the warmest recorded in Spain, with an average temperature of 25.7 ºC and 2.6 ºC above usual. A heat that does not give a break, not even at night. This is why many Spaniards choose to leave the fan or even the air conditioning on during the early hours of the morning, which will end up increasing the electricity bill.
Meteorologists warned of the risk due to the extreme temperatures that have been experienced in some autonomous communities, even going so far as to activate the orange warning. A situation that, especially in the south and northeast of Spain, will cause the much feared tropical nightsin which the thermometer will not drop below 20 degrees.
To improve the quality of the soil and be able to be rested the next morning despite the heat, many Spaniards will choose to leave the air conditioning on overnight. A decision that, although it will alleviate the thermal sensation of your rooms, will also cause a increase in your electricity billespecially if you have an air conditioner that uses a lot of energy.
Data necessary to calculate the energy consumption of an air conditioner
In order not to get scared when the receipt arrives, it will be necessary learn to calculate the cost of leaving this appliance on depending on the price of electricity established for each day. An account that, although it seems complicated, is quite simple, since you only need know the price per megawatt hour for that day and the energy expenditure of the model that is installed.
On average, the standard air conditioners in Spanish homes They usually have a consumption of between 900 and 3,000 watts per hour. A figure much higher than that required by other air conditioning devices such as floor or ceiling fans; However, they also tend to have a more noticeable and long-lasting effect on the temperature of the home.
Once this figure is known, which generally appears on the technical specifications sticker or, failing that, in the instruction manual, it will be necessary to look for the price of electricity for that day. As of August 15, 2026, The price of electricity has fallen to 116.51 euros per megawatt hourthat is, 16.83% less than the previous day, according to the Iberian Energy Market Operator (OMIE).
How to know how much it costs to leave the air conditioning on all night
Taking these data into account, it will only be necessary to do a series of calculations. In the event that the air conditioning has an energy consumption of 2,000 W (watts), it must divided by 1,000,000 to calculate your expenditure in megawatts; That is, the device consumes 0.002 MW every hour. This figure should multiplied by the hours it will be on; If you leave it overnight, it should be multiplied by 8 hours.
This account gives a result of 0.016 MW of total energy expenditure only counting the 8 hours of the night. With this figure, you can calculate the cost it will have, simply multiplying it by the price of electricity for this day in megawatts. Being 116.51 euros, keep the air conditioning on tonight It will cost approximately 1.86 eurosmore on the electricity bill.
However, it should be taken into account that the price used to make this account is the average of August 15, 2026 and that This figure may increase depending on the time slot or the contracted rate.. Therefore, to know the exact price, it will be necessary to take into account this entire series of factors.