Rain and fog at five points along the M4 climb over the Dilijan tunnel and Semyonovka pass to Sevan — with the official channels that announce closures. Not a road-status service.
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One tunnel carries almost all of Dilijan's traffic to Yerevan. The M4 climbs about 800 metres out of the forest valley to the roughly 2.25 km Dilijan tunnel near Semyonovka, then drops to the Lake Sevan basin and runs on down to the capital. This page reads the weather model at five points along that climb — the fog that settles in the valley, the rain, and what the higher pass is driving through — so you can see the conditions before you commit to the road.
Check these before you set out — they are the road status; this page is only the weather.
The Road Department Foundation publishes live interstate-highway status on Armenia's National Services Gateway (hartak.am) and the "Arm Roads Info" app; Armenia's rescue service, 911, responds to emergencies and severe-weather closures. This page reads weather along the corridor — it never says whether the road is open.
Over the next two days the model puts the most rain at the tunnel approach — 1 mm, almost no rain.
The lowest visibility it expects in the next 24 hours is dense fog at the tunnel approach (02:00–03:00).
These are weather-model estimates for grid cells, not measurements — and weather figures are never a road status.
Along the M4 to Yerevan, from town to the far end — the order the trip goes.
The forest-valley town where the trip starts or ends — cool, humid mornings and valley fog are common here.
The roughly 2.25 km tunnel on the M4 — the single chokepoint to Yerevan, reached by an 800 m climb out of the valley.
The higher road over the top, the only way round when the tunnel is shut — the most exposed point on the route, first to fog and snow.
Every figure here is a weather model’s estimate for an area, not a rain gauge and not a road camera. A model cannot see a landslide, a rockfall, roadworks or a closure.
Snow and ice are the winter hazard this weather model does not show. From roughly December to March the tunnel approaches and the ~2,000–2,114 m pass can hold snow and black ice under a clear sky, and heavy snow occasionally closes the M4 for a time even though the road is normally cleared and open year-round. Treat the rain and fog figures as background about the drive, never as an all-clear on the road.
This page describes the weather along the corridor. It cannot say whether the road is open, and it is never a judgement that driving is safe.
Nearly all Yerevan traffic funnels through the roughly 2.25 km Dilijan tunnel on the M4, reached by an 800 m climb out of the forest valley. The only way round is the older Semyonovka pass road, which tops out near the village at about 2,114 m — higher, more exposed, and the first stretch to fog over or hold snow.
Source: Dilijan — Wikipedia; points geocoded on OpenStreetMap, checked 13 July 2026 (today).
The government decided in 2025 to build a second tunnel beside the existing one, with design and budget documents completed that year. Expect recurring works and occasional night closures on this stretch for years — check the official road channels rather than older trip reports.
Source: NewsArmenia — new tunnel beside the Dilijan tunnel, checked 13 July 2026 (today).
January is the coldest month in Dilijan, averaging about −2 °C by day and −12 °C at night, with snow roughly December through March and around ten snow days in January. The town stays accessible, but the pass and the tunnel approaches are where snow and ice bite first.
Source: Weather Atlas — Dilijan January, checked 13 July 2026 (today).
Heavy rain and spring and autumn snowmelt are Dilijan's documented climate bite — they overwhelm the water intake and turn the tap water brown. Cool, humid mornings bring valley fog. Neither closes the road on its own, but both are what the model here can actually see.
Source: Town research: geography and local voices, checked 13 July 2026 (today).
Updated 13 July at 17:30. Weather figures are model estimates from Open-Meteo (CC BY 4.0), read at the points named above; ridge points use an elevation setting so the model downscales to that height. Visibility is worded on the WMO/NWS scale (fog below 1,000 m, dense fog below a quarter mile).
Where the road comes off the pass and meets the open Lake Sevan basin.
The lakeside junction where the mountain section ends; from here the highway runs on down to Yerevan.