Pro WeatherHow to Send Station Data to Weather Underground and CWOP
Your weather station produces a reading every few seconds, and most of the time nobody sees it but you. Sharing that data with networks like Weather Underground and CWOP changes that: your readings join public maps, fill gaps between official observation sites, and — in CWOP's case — feed directly into systems forecasters actually use. If your station runs on Davis WeatherLink, both uploads are built in. No bridge hardware, no extra software, no PC left running overnight. This guide walks through setting up each network, the ID formats that trip people up, and what to check when a station refuses to appear.
Why share your weather station data?
Sharing puts your readings to work beyond your own dashboard. CWOP feeds them into NOAA's MADIS system, where they support forecasting and research, while Weather Underground gives your station a pin on a public map that neighbors actually check. You also get free quality feedback, because your data sits right next to nearby stations.
Official observation networks are surprisingly sparse — in many regions the nearest professional site is an airport tens of kilometers away. Personal weather stations fill the gaps, which is exactly why NOAA runs a program to collect them. There is a selfish benefit too: network quality checks compare your readings against your neighbors, and a station that consistently reads warm or dry stands out quickly. That kind of feedback often reveals a mounting problem you would otherwise never notice — see our weather station siting guide for the usual culprits.
How do WeatherLink's third-party uploads work?
WeatherLink.com can push your data to Weather Underground, CWOP, and a handful of other services directly from Davis's servers. Log in at weatherlink.com, open your station's settings, and look for the uploads section. Enter the ID (and key) each network gives you, and Davis forwards your data automatically.
The uploads work on the free Basic plan — you do not need a paid subscription to share data. What the plan changes is cadence: Basic sends to third parties roughly every 15 minutes, Pro every 5 minutes, and Pro+ as often as every minute. We break the tiers down in WeatherLink Basic vs Pro vs Pro+. Note that these uploads are separate from the WeatherLink v2 API: the API key you would generate for your own programs or services plays no role here, because the network uploads run entirely on Davis's side.
How do I register a station with Weather Underground?
Create a free account at wunderground.com, then open My Profile → My Weather Stations and add a new device. A short wizard asks for your location and hardware type, then issues a station ID and a separate station key. Enter both into WeatherLink's Weather Underground upload settings, and data starts flowing.
The station ID format catches people out. A US ID looks like KXXCITY123 — K, a two-letter state code, a city abbreviation, and a number — while stations outside the US typically start with I. The ID is always all capitals, and an O or I next to the digits is easy to misread. The station key is a separate credential, generated per station and case-sensitive, so type it carefully rather than trusting a paste. And keep the networks straight: a Weather Underground ID never looks like CW1234. Putting a CWOP ID in the Weather Underground field (or vice versa) is one of the most common reasons an upload silently fails.
What about CWOP — and do I need a ham license?
No license is needed. CWOP, the Citizen Weather Observer Program, is open to anyone with an internet-connected station. Register through the sign-up form linked from wxqa.com and you will receive an ID such as CW1234 or DW5678; radio amateurs may use their call sign instead. That ID goes into WeatherLink's CWOP upload settings.
CWOP is less about a pretty public page and more about contribution. Your readings travel to CWOP's servers and on to NOAA's MADIS system within minutes, where they support forecast verification, research, and mesoscale analysis — the National Weather Service actively encourages station owners to join. Sending data every 5–15 minutes is the norm; pushing faster adds nothing and is discouraged. Be patient after signup: a new station can take 24–48 hours to show up in some downstream tools. Once flowing, wxqa.com ("weather quality assurance") publishes automated quality checks for every station, comparing your readings against analysis fields and neighbors over hourly, daily, weekly, and monthly windows.
Weather Underground vs CWOP at a glance
| Weather Underground | CWOP | |
|---|---|---|
| ID format | KXXCITY123 plus a separate station key | CW1234 / DW5678, or a ham call sign |
| License required | No | No — ham call sign optional |
| Where the data goes | WU's public map, pages, and apps | NOAA MADIS, forecasters, research |
| Public station page | Yes, a full PWS dashboard | Minimal — data surfaces via third-party tools |
| Typical send cadence | As fast as your plan uploads | Every 5–15 minutes |
| Quality feedback | Basic status flags | Detailed QC reports at wxqa.com |
Can I upload to multiple networks at once?
Yes. WeatherLink's upload settings let you enable several networks simultaneously, and Weather Underground plus CWOP side by side is a common combination. Each network has its own ID field and runs independently, so a misconfigured entry for one does not affect the others.
Running both makes sense because the networks serve different purposes: Weather Underground gives you a visible public page, while CWOP quietly makes your data useful to meteorology. Beyond those two, networks like PWSWeather, AWEKAS, and Windy also accept station data — we cover who each one suits in our rundown of Weather Underground alternatives.
Why isn't my station showing on the network?
The usual cause is a credentials slip: a mistyped station ID, a lowercase letter in what should be an all-caps ID, the case-sensitive Weather Underground key entered wrong, or a CWOP ID pasted into the Weather Underground field. Confirm WeatherLink shows the upload as active, then give it time.
A quick checklist when a station stays invisible:
- Check the ID character by character. All capitals, and watch for O/0 and I/1 mix-ups.
- Use the station key, not your account password. Weather Underground issues a separate key per station.
- Confirm the right network's ID is in the right field in WeatherLink's upload settings.
- Wait out the CWOP delay. MADIS ingestion is fast, but some map and lookup tools take a day or two to list a new station.
- Look up your CWOP ID on wxqa.com. If packets are arriving, the QC pages will show them — that tells you whether the problem is upstream or downstream.
A pin on their map, or a home of your own?
Sharing with networks and having your own website solve different problems. A network gives your station a pin on someone else's map, in their layout, under their branding. Your own site gives your station a real home — your design, your domain, your complete history. Many owners sensibly do both.
Pro Weather covers the second half: it turns a WeatherLink station into a fully hosted website with live conditions, charts, records, and forecasts, on your own domain if you want one. Because it reads the API rather than the upload feeds, it runs happily alongside Weather Underground and CWOP uploads — and you can embed the live data in an existing site or blog too. Contribute your readings to the networks for the common good; keep a Pro Weather site as the place that is unmistakably yours.
Common questions
How do I get a Weather Underground station ID?
Sign up for a free account at wunderground.com, go to My Profile → My Weather Stations, and add a new device. The registration wizard asks for your location and hardware, then generates a station ID (like KXXCITY123) and a separate case-sensitive station key. You need both for WeatherLink's upload settings.
Do I need a ham radio license for CWOP?
No. CWOP grew out of the amateur radio community, but internet-connected stations need no license at all. Register through the form linked from wxqa.com and you receive a citizen ID such as CW1234 or DW5678. Licensed radio amateurs can use their call sign as their station ID instead, but it is entirely optional.
Why isn't my station showing on Weather Underground?
Check the credentials first: the station ID must be entered in all capitals exactly as issued, and the station key is case-sensitive. Make sure you didn't enter a CWOP-format ID by mistake. Then confirm WeatherLink lists the upload as active and give it a few upload cycles — on the Basic plan that means 15-minute intervals.
Can I upload to multiple networks at once?
Yes. WeatherLink's upload settings support several networks at the same time, each with its own credentials, and they run independently. Sending to Weather Underground and CWOP simultaneously is common and causes no conflicts. Your own website is also independent of both, since services like Pro Weather read the WeatherLink API rather than the upload feeds.