Mesonet Station Status

A real-time station status map for the Montana Mesonet, built and operated by the Montana Climate Office.

About

Shows the current reporting state of every station across the HydroMet and AgriMet sub-networks. Two view modes:

• Status — single threshold: dot color reflects whether the station has posted within the last 2 hours.
• Time since — five bins of "minutes since the latest record," ceiling at >24 h.
• Health — three classes. Operational: reported within the last 2 hours with every expected sensor present. Partial: reported within the 2 hours, but one or more expected sensors are null in the latest record (the popup lists them). Total outage: no report in the last 2 hours, or no record at all.

In Health mode the legend footer reports sensor-list loading progress and, afterwards, how many fresh stations have no sensor list (those count as operational).

Color is Crameri's roma from the house palette (MCO.palette, mco-web-style 0.12.0), sampled at 0.1–0.9 and reversed: blue = fresh → pale → brown = stale. It is perceptually uniform, ordered, and safe for the major color-vision deficiencies, and the two ends differ in lightness, so they survive grayscale.

Other features:

• HydroMet / AgriMet sub-network toggles with live counts. Hiding a network dynamically resolves any stacked sites at that location to single dots.
• Search box with a custom themed dropdown (8 results, scored by relevance), keyboard navigation (↑ ↓ Enter), and a / global shortcut to jump to it from anywhere on the page.
• Plotly-style interactive legend in the lower-left: click a row to hide/show that category; double-click (or Shift+Enter) to isolate it. Every row shows the live count and share of the selected networks' stations in that category (label, count, percentage); hiding a category never changes its count.
• Co-located sites — the HydroMet station is always the visible anchor with a count badge. Hover (desktop) or tap (mobile) to fan the others out; a second click on a foot opens that station's popup.
• Toggleable station-ID labels with collision-based dodging.
• Hover tooltip with station name, ID, latest timestamp, and relative time — all in the viewer's local timezone.
• Tribal lands overlay — the 7 federal reservations in Montana drawn as a subtle fill + outline, with names at zoom ≥ 7.
• Montana state outline so the state shape reads as the primary frame.
• Dark → light → high-contrast theme button (high contrast uses the dark basemap) with neutral CARTO Positron / Dark Matter basemaps designed as data-overlay canvases.
• Map controls: zoom in/out + a "zoom to full extent" button (top-right). Zooming out below the state-fit zoom springs back; resizing the window also snaps back if the viewport drops below fit.
• First-visit help dialog auto-opens once so newcomers get the orientation.
• Honors prefers-reduced-motion and prefers-color-scheme.

Sharable URLs

Every piece of UI state is mirrored to the URL via history.replaceState. The view is fully shareable and bookmarkable.

Param	Values	Notes
lng	float	Map center longitude. Omitted at the default Montana fit.
lat	float	Map center latitude. Omitted at the default Montana fit.
zoom	float	Map zoom. Omitted at the default Montana fit.
mode	status | timesince | health	Visualization mode
net	+/space/comma list (hydromet+agrimet)	Active sub-networks. Empty = none. Case-insensitive.
scat	list (fresh+stale, null)	Visible Status-mode categories. Omitted = all.
tcat	list (0+1+2+3+4, null)	Visible Time-since bins (0 = <2 h, 4 = >24 h). Omitted = all.
hcat	list (operational+partial+outage)	Visible Health classes. Omitted = all.
labels	on | off	Station-ID labels
legend	open | collapsed	Legend panel state
theme	light | dark | high-contrast	Theme override. Omitted when it matches the OS preference.
station	station id (e.g. aceabsar)	Open this station's popup on load; deep-link

Precedence per setting: URL param > localStorage > built-in default.

All enum-string values (mode, theme, labels, legend, network names, category keys, station IDs) are matched case-insensitively. List params accept +, spaces, or commas as separators.

Examples:

/?station=aceabsar
/?station=aceabsar&lng=-109.61&lat=45.56&zoom=12
/?mode=timesince&net=agrimet&theme=light&labels=on&legend=collapsed
/?net=hydromet+agrimet&scat=fresh+stale

Data sources

• Stations + metadata: https://mesonet2.climate.umt.edu/api/stations/?type=json
• Latest record per station: https://mesonet2.climate.umt.edu/api/latest/?type=json
• Expected elements (sensors) for the whole network: https://mesonet2.climate.umt.edu/api/elements/?all=true&type=json (one request; rows carry a station column). If the API doesn't serve all yet, it ignores the flag and returns the bare catalog, which the app detects by the missing station column and falls back to the per-station form https://mesonet2.climate.umt.edu/api/elements/<station>/?type=json (e.g. https://mesonet2.climate.umt.edu/api/elements/acemidwa/?type=json). Without type=json the endpoints return HTML; per-station rows are duplicated and are de-duplicated by element.

Health cross-references the two: an expected element whose description_short column ("<description_short> [<unit>]") is null in the station's latest record counts as a sensor not reporting. The element lists are fetched once (one bulk request, or 8 concurrent per-station requests on the fallback path, ~10 s cold for the full network) and cached in localStorage under mco-status-elements-v1 with a 24 h per-station TTL, so a reload paints Health from cache immediately. Clear that key (or the site's storage) to force a refetch. Stations whose list fails to load are counted as operational when fresh and called out in the panel footer.

All API reads go to mesonet2.climate.umt.edu (the page CSP's connect-src pins that host). The per-station dashboard link stays on mesonet.climate.umt.edu/dash/.

The latest endpoint is polled every 5 minutes. Each response is merged into our in-memory store rather than replacing it — the Mesonet API occasionally drops a (different) station per call, and merging keeps a station's last-known timestamp from flickering to "no record" between polls. If a station genuinely stops reporting, its timestamp just ages naturally into the very-stale bin. Dot colors are also refreshed every 30 seconds against the local clock so freshness stays current between API calls.

Static overlay GeoJSON files in data/ (state, reservations, counties) are built by data.R from tigris + rmapshaper and checked into the repo so the app has zero runtime dependencies beyond the Mesonet API.

Development

The app is a single static index.html with no build step. Serve it locally with any static server:

# Python
python -m http.server 8000

# Node
npx serve .

Open http://localhost:8000.

Deployment

Published via GitHub Pages from the main branch. To enable for a fresh fork:

1. Push to main.
2. Repo → Settings → Pages → Build and deployment → Source: Deploy from a branch, Branch: main / (root).
3. Site goes live at https://<owner>.github.io/mesonet-status/ within a minute or two. Add a CNAME file later if you want a custom subdomain.

Social preview image

.github/workflows/preview.yml runs nightly (and on manual dispatch) and commits assets/og-card.png back to main — always pull/rebase before pushing, or you race it.

scripts/generate_preview.py screenshots the live Pages site at 2400×1260 (a 1200×630 viewport at 2×) with ?mode=status, which pins the Status view and, as a deep link, keeps the first-visit help dialog closed. It waits for the #refresh-stamp text to read refreshed … and then 4 seconds for tiles to paint — that param, element id and stamp text are a contract with the script. Run it locally to check:

pip install playwright
playwright install --with-deps chromium
python scripts/generate_preview.py

Tooling

• MapLibre GL JS v6.11.2 via CDN (imported by mco-web-style's MCO.map.loadMapLibre(); SRI in the import map).
• mco-web-style 0.16.2 (pinned + SRI).
• CARTO Basemaps Positron + Dark Matter (neutral data-vis backdrops, free, no API key).
• Vanilla JS / HTML / CSS — no bundler, no framework.

License

MIT — Copyright (c) 2026–present Montana Climate Office