If you've just added a temperature or humidity sensor to Apple Home — whether that's an IKEA TIMMERFLOTTE, an Eve Weather, an Aqara sensor, or even a HomePod mini using its built-in sensor — you might be wondering what to actually do with the data beyond watching the numbers change.

The answer is automations. And the good news is that Apple Home handles basic temperature and humidity triggers without any third-party apps, workarounds, or extra hardware beyond what most people already have.

This guide covers how to build those automations, what Apple Home can and can't do natively, and where iOS Shortcuts fills the gaps when you need more control.

WHAT YOU NEED

Before you start, you need two things:

A home hub. This is what runs your automations when you're not at home and keeps everything ticking overnight. A HomePod, HomePod mini, or Apple TV 4K (second generation or later) all work.

A temperature or humidity sensor visible in the Home app. This can be a dedicated sensor like the TIMMERFLOTTE, a multi-sensor that includes temperature, or even a HomePod mini (which exposes its built-in temperature and humidity sensor to Apple Home, though it's not the most accurate thing in the world).

If you have both of those, you're ready.

BUILDING A BASIC TEMPERATURE AUTOMATION

This example turns a smart plug on when a room gets too cold — useful if you have an electric heater, a fan heater, or any other device plugged into a smart plug.

1. Open the Home app on your iPhone or iPad.

2. Tap the Automation tab at the bottom.

3. Tap + and select Add Automation.

4. Under the trigger options, choose A Sensor Detects Something.

5. Select your temperature sensor from the list — make sure you pick the right one if you have sensors in multiple rooms.

6. Choose your trigger direction:

   • Rises Above — useful for triggering cooling: fans, AC, or closing smart blinds.

   • Drops Below — useful for triggering heating: a heater plug, a radiator valve, or a notification.

7. Enter your threshold temperature. Use realistic values — 18 °C as a "too cold" trigger, 24 °C as a "too warm" trigger — rather than edge cases you'll never hit.

8. Optionally, restrict the automation by time of day or presence. "Only between 10 pm and 7 am" or "only when someone is home" can stop automations firing at odd times.

9. Tap Next, then choose what happens — a scene, a specific device, or a combination.

10. Tap Done.

Avoid the on/off cycling problem If you set a single automation to turn a heater on below 18 °C, Apple Home will keep triggering it every time the temperature dips below that threshold — which can cause rapid cycling. Build two automations instead: one to turn the heater on when temperature drops below 18 °C, and a second to turn it off when it rises above 20 °C. That gap between the two thresholds gives the room time to stabilise.

BUILDING A HUMIDITY AUTOMATION

The process is identical to temperature — just swap the sensor type. Humidity automations are especially useful for bathrooms, bedrooms, and anywhere that gets damp in summer.

Some practical setups:

Bathroom extractor fan — If you have a smart plug on your extractor fan, you can trigger it automatically. Set humidity to turn the plug on when humidity rises above 65%, and off again when it drops below 55%. This handles post-shower ventilation without any manual switching.

Bedroom dehumidifier — Bedrooms in older UK homes can get uncomfortably humid in winter. A dehumidifier on a smart plug triggered at 60% humidity is a simple, effective fix.

Damp alert — If a room's humidity climbs unusually high and stays there — a sign of a ventilation problem or damp — you can trigger a notification rather than a device. Set the action to send you an alert via the Home app so you find out before it becomes a bigger issue.

Humidity accuracy varies If you've read the IKEA TIMMERFLOTTE review, you'll know that budget sensors often read humidity a few percent higher than the actual value. That's fine for comfort monitoring and automation triggers — just set your thresholds to account for it rather than treating the number as lab-accurate.

GOING FURTHER WITH IOS SHORTCUTS

Apple Home's built-in automation editor handles simple threshold triggers well. Where it falls short is more complex logic — things like "only trigger if both temperature and humidity are above a threshold" or "trigger at a specific time and only if the temperature has already exceeded a value."

For that, you convert the automation to a Shortcut.

The broad pattern is: set the Home automation to run when a sensor detects something, but instead of selecting a device or scene as the action, select a Shortcut. That Shortcut can then check other conditions, read from multiple sensors, and take different actions depending on what it finds.

A practical example: a fan that runs only when it's both warm and humid — above 23 °C and above 60% humidity — rather than on temperature alone. In Apple Home, you can't combine those triggers natively. In a Shortcut, you can check the temperature reading, then check the humidity reading, and only proceed if both conditions are met.

More on Shortcuts-based automations If you want to build this kind of logic, Convert Home Automations to Shortcuts walks through the process in detail.

SOME AUTOMATIONS WORTH BUILDING TODAY

If you've just added a TIMMERFLOTTE or similar sensor and want somewhere to start, here are a few that are immediately practical:

Cold bedroom alert — Temperature drops below 16 °C between midnight and 6 am → send a notification. This is especially useful if you have young children or elderly family members in the house.

Summer fan trigger — Temperature rises above 25 °C when someone is home → turn on a fan plug. Drops below 23 °C → turn it off.

Colour temperature shift — If you have smart bulbs, you can use temperature as a subtle visual cue. Drops below 16 °C → shift lights to a warmer tone. Rises above 26 °C → shift to cooler white. It doesn't do anything practical, but it adds a layer of ambient awareness to the room.

Post-shower humidity clear — Humidity rises above 65% → turn on extractor fan. Humidity drops below 55% → turn it off. Set this with a time restriction of any time to make it always active, or restrict it to mornings and evenings if you want to limit when it can trigger.

A NOTE ON SMART PLUGS AND HEATER SAFETY

Before you automate any heating device, it's worth pausing on one practical safety point: not all smart plugs are rated for heaters.

Most heaters — even compact fan heaters — draw between 1,000 W and 2,000 W when running. Some smart plugs are only rated to 10 A (roughly 2,300 W at UK mains voltage), which puts a 2 kW heater right at the limit. Others are rated lower. A plug running consistently at or near its maximum rated load will run warm, and over time that increases the risk of failure — or worse.

Before you connect a heater to a smart plug, check two things:

1. The heater's wattage — this is on the label, usually on the base or rear of the unit.

2. The smart plug's rated load — listed in the product specs, often on the plug itself.

The smart plug's wattage rating must comfortably exceed the heater's draw. As a rule of thumb, aim for the heater to use no more than 80% of the plug's rated capacity. So for a 2,000 W heater, you want a plug rated for at least 2,500 W (or ~11 A) — ideally more.

Some other things worth keeping in mind:

• Only use smart plugs that carry a BSI Kitemark or CE marking (or both). These indicate the plug has been tested to UK or European safety standards.

• Never use an extension lead or multi-way adapter between the smart plug and the wall socket. Heaters should always be plugged directly into a wall socket — smart plug included.

• Keep the area around the heater clear. Automations make it easy to forget a heater is running. Make sure there's nothing flammable nearby before you set an automation that could turn it on while you're asleep or away.

• If your heater doesn't have its own built-in overheat or tip-over protection, consider whether automating it unattended is the right call at all.

The smart plugs that tend to work well for high-draw appliances include the Eve Energy (rated to 2,300 W / 10 A), Meross MSS210 and Kasa EP25 — but always verify the current specs before buying, as ratings can change between product revisions.

When in doubt, don't automate it An automation that turns a heater on at 3 am while you're asleep is only a good idea if you're confident in the equipment involved. If a smart plug feels warm to the touch during normal use, that's a sign it's working harder than it should be. Replace it before automating anything high-draw through it.

A NOTE ON SENSOR PLACEMENT

Automations are only as useful as the readings they're based on. A temperature sensor placed in direct sunlight, next to a radiator, or in a draught will give you inaccurate readings — which means your automations will trigger at the wrong times.

For reliable results, place sensors away from heat sources, out of direct sunlight, and somewhere with reasonable airflow. Windowsills work well in most rooms as long as the sensor isn't in a south-facing spot that gets direct afternoon sun.

READ NEXT

• IKEA TIMMERFLOTTE Review: The Best Budget Temperature and Humidity Sensor for Apple Home?

• Convert Home Automations to Shortcuts (and Why You'll Want To)

• Matter, Thread, Wi-Fi and Bluetooth: What Actually Matters in Apple Home