Plenty of factors contribute to the temperature inside your house, like the climate, construction, and the heating and cooling system you install.
Ideally, your home stays at a comfortable temperature all year round, and although different people have different comfort levels, how hot is too hot inside your house?
Is 80°F (26.6°C) too hot for a house in summer?
What Is an Ideal Room Temperature?
The ideal room temperature depends on:
- Occupant age – young and old are more vulnerable to extreme cold and heat.
- Activity levels – body temperature drops when sitting still.
- Room usage – a home office needs a warmer temperature than a bedroom.
- Time of day combined with room usage and occupancy.
- Seasonal climate changes.
- Room position – upstairs rooms benefit from rising heat.
- Humidity – high humidity means you need a lower room temperature for comfort.
Seasonal House Temperatures
You need your house to be a cozy haven in winter, but you may need a cooling retreat from scorching heat in summer.
Climate control inside your home is essential for your health and comfort.
What Temperature Is Too Hot for a House in Summer?
In summer, you run a cooling system to reduce the heat inside the house compared with outside.
The ideal temperature range for most people in summer lies between 68°F (20°C) and 76°F (24.4°C).
Taking your room temperature down to 68°F (20°F) may feel blissful but will cost you more on your energy budget.
A daytime temperature of 72°F (22.2°C) compromises cooling for comfort and expensive energy costs, and this temperature allows you to be comfortable inside in light clothing.
During hot summer nights, you can allow the temperature inside your house to rise to 78°F (25.5°C) – 80°F (26.6°C) to reduce energy costs. Provided you sleep with a thin (or no) sheet, you will be comfortable overnight.
If the high humidity makes sleeping uncomfortable, consider a dehumidifier to increase comfort.
When you leave your house for work or a vacation, you still need cooling to keep the house below 80°F (26.6°C).
Above this temperature, you risk damage to the structure of your home from a combination of heat and humidity.
What Temperature Is Too Hot for a House in Winter?
In theory, you can heat your house to allow you to wander comfortably round in shorts and T-shirts while there is snow on the ground outside.
During winter, the best average temperature in a well-insulated house is a relatively cool 64°F (17.7°C) when awake and moving.
Switching your ceiling fan direction in winter can warm the indoors while reducing heating.
At night you can reduce the heating levels to 62°F (16.6°C) and rely on blankets and duvets to maintain your body in comfort and warmth.
If you need to leave your house empty while at work, maintain heating to prevent the internal temperature from falling below 55°F (12.7°C); allowing your house to grow too cold results in problems with ice in pipes and dampness.
However, there is little point in excessively heating your home when no one can enjoy the warmth and comfort.
How Cool Should Your House Be When Outside It Is 90°F-100°F?
Cooling your house means dropping the room temperature compared to the external air temperature. The best cooling systems for homes rarely manage a differential of more than twenty degrees.
That means when the temperature outside is 100°F (37.7°C), the best you can hope for is an indoor temperature of 80°F (26.6°C).
Your body temperature is 98°F (36.6°C), and the level of heat you experience depends on humidity and temperature.
A wet-bulb temperature of 95°F (35°C) causes severe heat-related health issues and can have fatal consequences if prolonged. The wet-bulb temperature accounts for a combination of heat and humidity and is different from air temperature.
For example, with 50% humidity, the danger level is 109°F (42.7°C), but you are relatively unharmed to 130°F (54.4°C) in a dry climate.
In practical terms, your house needs to provide sufficient cooling to provide a safe environment for your most vulnerable family members.
What Is the Impact of Humidity on Ideal Room Temperatures?
Humidity is a measure of water vapor in the air.
Your body cools down by releasing water vapor from your skin and adding (a tiny amount) to the humidity in your room.
If the humidity is high, you find it challenging to cool down naturally, and you feel hotter than the actual temperature in the room compared to one with a drier atmosphere.
Low humidity can equate to feeling like the room is up to six degrees cooler because of sweat evaporating from your skin.
Your house and you need humidity of 30-50%, so setting your ideal room temperature in winter and summer needs a balance between heating, cooling, and humidity levels.s
A dehumidifier can remove excess moisture from the air, and a humidifier can alter a too dry room into a healthier one.
Why Your House Gets Hotter than the Outside
Some solutions are simple and easy to implement; others may cost more and professional help can be handy.
How Hot Is Too Hot for Sleeping?
Not heating a room overnight while you sleep saves money on the heating bill, but many people need air conditioning to take the room down to an acceptable nighttime temperature in a hot summer.
Your internal body temperature drops by a few degrees, and normal biological processes slow down when you sleep. Most health gurus promote a cooler room for more restorative, restful sleep.
But how hot is too hot for overnight?
Sleeping at a room temperature of 87°F (30.5°C) to 100°F (37.7°C) interrupts natural sleep and prevents the REM cycle (Rapid eye-movement) and deep sleep necessary to restore your body and brain.
The ideal room temperature for optimum sleep varies with individuals from 60°F (15.5°C) to 72°F (22.2°C), depending on the thickness of bed coverings and if you sleep with a partner.
Is 75°F to 79°F Too Hot for Sleeping?
Although these temperatures are not in the ideal range, you may be pretty comfortable overnight with minimal bedding if you live in a dry climate.
The ideal nighttime temperature guides potential comfort rather than a fixed rule.
Other factors impacting your quality of sleep include humidity and anxiety.
Most people have restless, poor-quality sleep in areas where high nighttime temperatures mean potential droughts, fire, and other disasters.
High temperatures are not the only factor in reduced sleep quality.
Is 80°F Too Hot for Sleeping?
The primary requirement for successful sleep is a cooler room temperature than your core body temperature.
Although 80°F (26.6°C) is higher than the ideal overnight room temperature, it is still possible to sleep successfully at this temperature – depending on the relative humidity.
How to Sleep at 80°F or 90°F?
If it is not possible to cool your bedroom to a more optimal overnight temperature, then you can take steps to get a decent night’s sleep despite the soaring temperature.
- Airflow – weather forecasters talk about wind chill, and you can use the same effect to cool down your sleeping body by using a fan. Air movement across your body allows your sweat to evaporate and cool you down. Don’t use a fan if the temperature rises above 95°F (35°C).
- Ditch the bedclothes – when it is this hot, you don’t need bedcovers. Some people need a cover to promote sleep, but a thin sheet will provide that comfort.
- A cool bath or tepid shower helps you cool down before getting to the bedroom.
- Hydration overnight – ensure you have a jug of chilled water to quench your thirst if you wake up hot and bothered.
- Bedding that actively cools – you can get breathable, cooling pillows and mattress toppers to help promote cooling comfort overnight.
- Keep the heat out during the day by closing curtains and blinds.
Various reasons can cause your house to feel hotter than the outside – day and night – but there are simple solutions you can adopt to restore comfort indoors.
When Is It Too Hot for a Sleeping Baby?
Babies have less control over heat regulation than adults, and your baby doesn’t sweat as effectively, and neither is your baby in control of its environment.
Heat exhaustion and dehydration are serious issues for your baby in scorching weather.
The ideal room temperature for your baby lies between 68°F (20°C) and 72°F (22.2°C) – the same as for an adult in hot weather.
However, you must dress your baby appropriately for the temperature. Your baby can’t throw off the blankets if it is too hot, so you need to ensure your baby is not too hot or too cold.
If you can’t cool the room, keep your baby cool, particularly when indoor temperatures rise above 80°F (26.6°C).
You can keep your baby cooler by:
- Wiping regularly with a cool cloth.
- Removing blankets and using light clothing.
- Keeping your baby hydrated.
- Providing plenty of natural airflow.
- Use thermal linings for your curtains to reflect heat from the room.
Why is Heat an Issue?
Excess heat contributes to early death for vulnerable people.
Babies are susceptible to convulsions and SID (Sudden Infant Death) when they get too hot.
Hot weather strains hearts and lungs, placing older people and vulnerable adults at risk of illness. Hyperthermia is similar to hypothermia, causing a potentially fatal impact from the closing down of natural body functions.
Heat can sap your energy and make it challenging to live normally.
Between 90°F (32.2°C) and 105°F (40.5°C), you can experience heat exhaustion and cramps associated with dehydration and other heat impacts.
Over 130°F (54.4°C), you are at severe risk of heat exhaustion.
Why Are Fans Dangerous Above 95°F?
A fan moves air around and doesn’t actively cool it, unlike air conditioning.
The cooling effect of a fan comes from the evaporation of moisture from your body.
Above 95°F (35°C), a fan can contribute to the heat problem by increasing your body temperature and preventing moisture evaporation from your skin.
A room fan is helpful when the air is cooler than your core body temperature, but it is not a substitute for air conditioning in a heatwave.
How Hot Is Too Hot Inside Your House?
The experience of heat is personal, depending on your age and circumstances.
Generally, when the temperature in your house begins to exceed 80°F (26.6°C), you need to take precautions to protect yourself, vulnerable family members, and pets from the damaging impact of heat.
High temperatures and humidity can destroy the fabric of your house.
Although you want to minimize your energy consumption, the benefit of a quality HVAC system is that you provide the ideal climate for health and wellbeing inside your home regardless of external conditions.