Is it raining now in Blackwood?
Sunny
5 OctNo upcoming precipitation for the next hour.
Last updated: 20:00, 5 Oct 2026
Free to download * Essential from $0.83 * Prices vary by region and promotions.
- App Only
Track up to 20 locations
Home, office, kids' school - all at once, no switching tabs.
- App Only
Alerts for each of them
Get notified 15 minutes before rain - while you can still change your plans.
- App Only
Widgets on your home screen
Live radar without opening the app - on your lock screen or home screen.
Rain in Blackwood: What You Need to Know
Blackwood sits in the Sirhowy Valley in the South Wales valleys, with steep wooded hillsides rising close on both sides and the River Sirhowy running through the middle of town. Rain gathering on those slopes reaches the valley floor fast, and the narrow shape of the valley channels it straight through the town. Anyone comparing a forecast with a Blackwood rain radar sees the gap quickly, since hyperlocal radar shows where the rain is and where it is heading.
Fronts cross the Irish Sea and the Bristol Channel and meet ridge after ridge of high ground. Orographic lift produces heavy rain over the valley heads, and the steep, narrow valleys send that runoff to the river towns within hours. The steep, wooded sides of the Sirhowy Valley lift Atlantic showers quickly, so the hillsides above Blackwood can be well soaked while the town centre on the valley floor is only just starting to feel the rain.
RainViewer's coverage of Blackwood, Wales, comes from Met Office radar, with the map updating on each new 5-minute scan. The live map shows whether a shower is still building on the hillside or already dropping into the Sirhowy Valley, which a forecast for Blackwood cannot tell you.
Rain by Season in Blackwood
Autumn and winter frontal season (September to January)
September through January is when Atlantic depressions and named storms arrive one after another, dropping persistent rain onto the hills. As the ground reaches saturation, rivers in the valleys rise fast, and mountain passes, valley roads and low-lying streets are usually the first to be affected. Winter fronts saturate the steep valley sides, and the Sirhowy can rise fast through the town after repeated bands.
Transition months (February to April)
Spring showers cross the valley quickly, and walks on the hillside paths above the town are the plans most often caught out. Hail, sleet and wet snow on the tops alternate with fronts. Forecasts fail because showers are narrow, and hill walks and weekend rugby are the most exposed.
Summer season (May to August)
Summer storms build over the valley on warm afternoons, and market day stalls and outdoor events depend on the gap between them. Rain eases off between May and August, though heavy showers and thunderstorms can still build over the hills on warm afternoons. Festivals, coastal trips and mountain walks all depend on finding one of the short dry windows in between.
Why You Need a Rain Radar in Blackwood
Sirhowy Valley walkers
The paths climbing the wooded hillsides above Blackwood leave shelter quickly, and a shower there can reach walkers before it reaches the town below. Checking the radar first shows how much time is left.
Blackwood market traders
Blackwood's market and high street stalls have little cover, and heavy rain can empty the street within minutes. Traders watch the radar to see whether a shower will clear before the next customers arrive.
A4048 valley road commuters
The A4048 running through the Sirhowy Valley links Blackwood to Caerphilly and Newport, and heavy rain on the steep sides can bring water onto the road fast. Watching the cell on the radar helps time the drive.
Sirhowy riverside walkers
The path beside the Sirhowy through town floods quickly after hill rain. Watching the cell on the radar shows whether to walk the riverside or take the higher street instead.
RainViewer Radar Coverage in Blackwood
RainViewer shows UK precipitation using data from the Met Office, the national weather service, which runs a network of C-band dual-polarization weather radars. The Met Office network also feeds the European OPERA composite, and the RainViewer map refreshes with each new scan, about every 5 minutes. From Blackwood the map also covers Caerphilly, Newport and Ebbw Vale.
Blackwood Rain Radar: Frequently Asked Questions
- How does rain affect market day in Blackwood?
Blackwood's high street market stalls have little shelter, and heavy rain off the surrounding hillsides can empty the street within minutes of the first drops. Traders and shoppers both watch the sky before setting up or heading out. RainViewer shows the shower building on the hillside before it reaches the town.
- Does rain affect the A4048 through Blackwood?
Yes, the A4048 runs along the Sirhowy Valley floor, and heavy rain on the steep sides above Blackwood can send water onto the carriageway with little warning. Checking the map before you set off shows the cell's position. RainViewer keeps the picture current with a refresh every five minutes.
- Does Blackwood flood when it rains?
The River Sirhowy can rise quickly through Blackwood after heavy rain on the steep valley sides, and low ground near the river through the town centre is the first to be affected. The streets higher up the hillside are rarely troubled. The radar shows whether more rain is falling on the slopes above.
- When is the best time to visit Blackwood to avoid rain?
May to August is the best window to visit Blackwood, when hillside showers are shorter and the Sirhowy Valley paths are at their driest. Spring can still bring quick, cold showers off the slopes. Check the radar in the morning and plan any hillside walk around the gap.
- Why can it rain on the town centre while the hillside above town stays dry around Blackwood?
Rain that gathers on the steep, wooded sides of the Sirhowy Valley reaches the hillside first, so the paths above Blackwood can be wet while the town centre on the valley floor stays dry a little longer. A forecast covers both places with one number, while the radar map shows the rain crossing the town centre and missing the hillside above town.
- Is the Blackwood weather map showing a live radar feed or a forecast?
The Blackwood weather map on RainViewer shows a live radar feed from the Met Office, refreshed roughly every 5 minutes, not a forecast probability. Wales is covered by Met Office C-band radar, and its dual-polarization data tells rain, sleet and hail apart even up on the Brecon Beacons and the valley tops. That hyperlocal radar feed is what sets it apart from a standard forecast app.
- What can I do with RainViewer in Blackwood beyond checking current rain?
Set a rain alert on the town centre or the A4048 and RainViewer warns you before rain arrives. That lets you time a market visit or a commute. The 2-hour forecast in 5-minute slices shows the next gap, and saved locations track the hillside above town and Caerphilly together.
Track Rain in Blackwood in Real Time
A walk on the hillside and a market morning in town both depend on a dry gap, and RainViewer shows the next one.
Showers off the Bristol Channel reach Blackwood quickly, and the gap between two bands is the window that matters.
The forecast says rain in Blackwood this afternoon. RainViewer's live hyperlocal radar shows the cell still building on the hillside with the town centre dry, which decides whether the market visit starts now.
Track rain in Blackwood — free Upgrade to Essential for alerts, forecasts, and full radar history
2-hour forecast in 5-minute slices
The 5-minute steps show whether the walk on the hillside fits inside the dry gap.
Rain alerts before arrival
Set the alert at the town centre, and the warning arrives in time to decide whether to start the market visit now or wait.
Direction arrows on the map
Storms usually arrive from the west and south-west, off the Irish Sea and the Bristol Channel over Blackwood, and the arrows show which way each cell is moving.
48 hours of radar history
Check the hillside above the Sirhowy Valley in the last 48 hours to see how much rain came down.
Multiple locations
Keep the town centre, the Sirhowy riverside and Caerphilly on the same list, each with its own alert.
RainViewer
