Garage & workshop sensor monitoring

ProbeHarbor

Know before your pipes freeze or your garage floods.

ProbeHarbor watches temperature and leak sensors in garages, workshops, attics, crawlspaces, and shops, with live charts, history, and freeze, leak, and heat alerts. Open source, with a free plan.

Start free See the live demo

No credit card. No hardware yet? Get free freeze alerts for your ZIP.

Free forever · no credit card Member $4/mo Pro $10/mo

ProbeHarbor Insights: seven-day probe curves with the freeze line, flood/wet contacts, nights-at-risk forecast, and forecast-backed time-to-freeze clock
Real ProbeHarbor dashboard: 30-day probe curves, freeze threshold, and week-over-year comparison, not a mockup.

Two ways to try it (no account)

Open the garage door and trigger a cold snap in the simulator, or watch the real demo probes below.

Try a cold snap Live demo feed

Loading probe temperatures…

Loading outdoor weather…

How it works

One recommended path: ESP32 + waterproof probe → ProbeHarbor → phone alert. Other boards and feeds stay supported after you are live.

  1. Build one probe

    ESP32 + waterproof DS18B20 is the default kit (~$20–30 parts): three wires and one resistor. A DHT22 adds humidity on the same pin.

  2. Install from your browser

    Plug the ESP32 into USB, install the firmware from the web flasher in Chrome or Edge, and send it your Wi‑Fi and device key over the same cable. No Arduino IDE, no code.

  3. Get freeze alerts

    Set freeze °F + email, send a test, then watch Live and Overview. Add a flood/leak contact when you are ready.

You need: a free account, an ESP32 board (about $8–15), a waterproof DS18B20 (about $2–5), your Wi‑Fi, and a USB cable with Chrome or Edge. Under about $25, no subscription to try freeze alerts.

Start free ESP32 parts list Other boards and integrations

Love DIY? You don’t have to DIY everything.

Keep your ESP32, Arduino, MQTT, or Home Assistant setup. ProbeHarbor adds hosted history plus household freeze and flood alerts without another server to babysit.

Your sensor. Your data. Your alerts.

Scenario

34°F. That’s when the alert matters.

Picture an attached garage where one corner dips below 34°F every clear night. The alert says something is wrong; the history chart shows where, pointing at a drafty door seal before supply lines ice. That is exactly the kind of timeline a claims evidence pack would document if freeze damage ever became an insurance conversation.

ProbeHarbor seven-day temperature trend with two probes, average, humidity percent, dew point overlay, alert markers, and 34°F freeze line
The same freeze line households set in Alerts, visible on History curves.

Read the scenario More scenarios

Protect vulnerable spaces

Freeze and leak alerts on every plan, plus a time-to-freeze clock for this space so you know when pipes will hit freeze, not only after they do. Member adds outdoor forecast warnings; Pro adds official NWS alerts and SMS. Cold-snap playbook

Catch leaks before they spread

Flood / leak contacts auto-alert when wet, even during snooze or vacation. Add a sump or tank level sensor if you want early-warning rules before water reaches the floor. Flood + level ingest guide

Your sensors, your stack

Temperature, humidity, air quality, doors, leaks, power, and motion on hardware you control. Ingest guide · HTTP API

Free to start

Pick a rung by job, whether that is freeze nights, wet leak alerts, or portfolio monitoring. Full limits live on pricing.

  • Free See if ProbeHarbor works for you
  • Member Track a whole cold season · $4/mo
  • Pro Serious alerts and automation · $10/mo
Start free Compare plans

Open-source dashboard and sample sensor sketches. View source on GitHub.

Frequently asked questions

Straight answers for homeowners wiring probes, wet contacts, and setting freeze or flood alerts.

What is ProbeHarbor?

ProbeHarbor is open-source freeze and flood monitoring for garages, workshops, attics, crawlspaces, and shops: ESP/Arduino ingest, live curves, and alerts. Build with ESP32, Pico W, or Arduino; ProbeHarbor handles the hosted dashboard, history, and household alerts.

How do I connect ESP32, Pico W, or Arduino sensors?

For an ESP32, the quickest path is the web flasher at probeharbor.dev/flash: plug the board into USB, install the firmware from Chrome or Edge, and send it your Wi-Fi and device key. It reads DS18B20 probes, a DHT22, or an I²C sensor (BME280, SHT31, AHT20), plus optional leak, door, and battery inputs. For other boards, create a push device under Dashboard → Devices and POST JSON to /api/ingest/<key>; sensors auto-import on first POST. Pico W and Arduino samples live on probeharbor.dev/about/adding-devices. No hardware? Try the demo pull quick start on Overview.

Do I need to know how to code?

No. With an ESP32, the web flasher installs prebuilt firmware from your browser and sends it your Wi-Fi and device key over the USB cable, so there's no Arduino IDE and nothing to edit. The firmware is open source if you'd rather read or change it, and the sample sketches are still there for other boards.

Does ProbeHarbor send freeze alerts?

Yes. Set a freeze threshold and enable channels such as email, browser or Android push, Discord, Telegram, Slack, or (on Pro) SMS and WhatsApp. Remaining-hours time-to-freeze alerts fire before the probe crosses freeze, using this space's lag vs the outdoor forecast (details: probeharbor.dev/about/time-to-freeze). Predictive outdoor forecast freeze alerts are on Member; official NWS freeze and cold alerts are on Pro. Leak / flood sensors also notify automatically when wet; door, motion, power, and air quality use custom rules. With a Telegram bot webhook, you can reply /status, /snooze, or /vacation from chat.

Is ProbeHarbor free?

Yes, there is a free plan with live curves, 7-day history, threshold freeze and leak alerts by email and push, and one family live share link (7-day expiry). Member adds 90-day history, CSV export, more devices, and forecast freeze warnings; Pro adds 1-year+ history, official NWS freeze and cold alerts, SMS, unlimited share scopes (history, metrics, never-expire), a printable claims evidence pack, webhooks, and a trial. Annual Member and Pro billing is discounted versus monthly.

Why do I need an account?

An account links your ingest keys, history, and alerts to your household: it is how we keep your probes private. Registration is free with no credit card. You can try the interactive probe simulator or watch the live demo without signing up; create an account when you are ready to connect your own hardware.

Is there a ProbeHarbor Android app?

A native Android app is available in early access on GitHub while Google Play review finishes. You can also use the full web dashboard or install the Progressive Web App. Companion clients (Android, Desktop, Bay Buddy, PWA) are listed at probeharbor.dev/apps. The phone and desktop apps do not sense temperature: they connect to your ProbeHarbor account.

Was ProbeHarbor called ThermalTrace?

Yes. ThermalTrace was renamed ProbeHarbor in October 2026 to avoid confusion with an unrelated product. Accounts, sensors, history, and alerts carried over unchanged. Old thermaltrace.dev links redirect here, and devices still posting to thermaltrace.dev ingest URLs keep working, though new setups should use probeharbor.dev.

Where is ProbeHarbor hosted?

On Cloudflare’s edge network (Workers), so the site and ingest APIs run close to visitors without you maintaining a VPS. Live job and ingest health is on probeharbor.dev/system-status: we publish what we measure, not a marketing uptime percentage.