Tracking Indoor vs Outdoor Temperature in an SF Apartment

I needed AA and AAA batteries and grabbed an IKEA TIMMERFLOTTE while I was at it. Zigbee temperature and humidity sensor, $8. I put it in my living room: middle of the apartment, between all the windows, so a reasonable representative reading. No real plan. Ten days of data later, I have a clear picture of how this apartment moves heat — and it is not great. Setup The TIMMERFLOTTE logs over Zigbee to Home Assistant. It reports on state change rather than on a fixed interval, so the data is dense: I get a reading whenever temp shifts by about 0.1°F. For outdoor data I’m using Pirate Weather, a privacy-respecting API that pulls from NOAA, exposed as a template sensor in HA: ...

July 29, 2026 · 5 min · Derek Welty

IKEA Varmblixt as a Home Assistant Status Light

I wanted a passive ambient display that tells me something useful without picking up my phone — weather at a glance during the day, a wind-down mode at night, green at 6:30am if it’s worth cycling to work. The IKEA Varmblixt is $30, Zigbee-native, and pairs directly to ZHA without an IKEA hub. Pairing Not obvious. There’s no reset button. To enter pairing mode, power-cycle the lamp 12 times in rapid succession — plug, unplug, plug, unplug… It flashes white 3–4 times when it’s ready. A smart plug makes this way easier than fumbling with the physical outlet. Source ...

April 13, 2026 · 5 min · Derek Welty