Average Rainfall in Cornelius Oregon

Learn about Average Rainfall In Cornelius Oregon

Curious about the Average Rainfall In Cornelius Oregon? Here’s the simple answer: Cornelius sees a wet, green climate with steady fall–spring rain and mostly dry summers. This guide explains how much rain to expect, when it falls, and how locals plan daily life around it.

Quick Answer

Cornelius averages about 41 inches of rain per year, with roughly 150 days of measurable precipitation. The wettest stretch is November–January; the driest months are July–August. Most rain comes as light showers or drizzle, with occasional heavy systems. Snow is rare—typically 1–3 inches total in a typical winter.

What Average Rainfall In Cornelius Oregon Means

  • The city sits between Hillsboro (east) and Forest Grove (west), near the Coast Range. That location brings a bit more rain than downtown Portland.
  • Expect 38–45 inches in a typical year depending on the neighborhood and the year’s weather pattern.
  • Rain is usually light to moderate, not tropical downpours—think jackets and hoods, not monsoon gear.

Why People Search for This in Cornelius, Oregon

  • Planning a move and wondering about yard care, gutters, or commute conditions.
  • Scheduling visits to Hagg Lake (≈25–30 minutes south) or Fernhill Wetlands (≈10 minutes west).
  • Choosing the best time for winery visits across the Tualatin Valley.
  • Deciding what gear to bring for kids’ sports, dog walks, or trail time.

What to Expect

Seasonal pattern:

  • Fall (Oct–Nov): Rains return. October brings a few inches; November is one of the wettest months (often around 6 inches). Occasional wind and “atmospheric river” events.
  • Winter (Dec–Feb): Steady rain and gray days. December and January are very wet (about 5–6 inches each). Snow is uncommon but possible—ice can be more disruptive than snow.
  • Spring (Mar–May): Showers and sunbreaks. March and April each bring a few inches; May starts to dry out.
  • Summer (Jun–Aug): Mostly dry. July and August often get under 1 inch combined. Warm, comfortable evenings; wildfire smoke can drift in some years.
  • Early Fall (September): Transition month—usually light rain returns late in the month.

Typical monthly rainfall ranges (approximate):

  • Oct: 2–4 inches
  • Nov: 5–7 inches
  • Dec: 5–7 inches
  • Jan: 4–6 inches
  • Feb: 3–5 inches
  • Mar: 3–4 inches
  • Apr: 2–3 inches
  • May: 1–2 inches
  • Jun: 1–2 inches
  • Jul: 0.2–0.7 inches
  • Aug: 0.3–0.8 inches
  • Sep: 1–2 inches

Local notes:

  • Downtown Cornelius and neighborhoods near TV Highway see similar totals to Hillsboro; areas closer to Forest Grove and the foothills trend slightly wetter.
  • Low-lying spots and leafy streets can see brief ponding during heavy showers.
  • Trails at Hagg Lake and Jackson Bottom Wetlands can be muddy after storms—waterproof footwear helps.

Tips for Visitors / Residents

Clothing and daily life:

  • Wear layers and a light waterproof jacket with a hood. Umbrellas are fine, but breezes make hoods easier.
  • Waterproof shoes or boots are worth it from November through April.
  • Keep a small towel in the car for foggy, damp mornings.

Home and car:

  • Clear gutters and drains each fall to avoid overflow.
  • Use all-weather tires; watch for slick roads after dry spells when oil lifts.
  • In freezing snaps, watch for black ice on shaded streets and bridges.

Outdoor fun:

  • Visit Fernhill Wetlands for birding after rain—bring binoculars and a hat.
  • Hagg Lake is great year-round; in wet months, stick to improved trails or paved paths.
  • Wineries with covered patios in Tualatin Valley make rainy-day tastings easy.

Commute and timing:

  • Heaviest rain is often overnight or early morning, with afternoon sunbreaks common in spring.
  • For the driest visit, aim for mid-July through mid-September.

Frequently Asked Questions About Average Rainfall In Cornelius Oregon

Q: How far is Cornelius from Portland?

  • A: About 25 miles west. Driving typically takes 35–55 minutes, depending on traffic via US-26 or TV Highway (OR-8).

Q: What months are best for dry weather?

  • A: July and August are the driest, with September often pleasant too.

Q: Does it snow much?

  • A: Not usually. Expect 1–3 inches total in a typical winter, with some winters seeing none and occasional short-lived ice events.

Q: Is the rain mostly heavy?

  • A: No. Most days bring light showers or drizzle. Strong storms do happen a few times each season, mainly in late fall and winter.

Q: Is Cornelius kid-friendly in rainy seasons?

  • A: Yes. Try the Cornelius Public Library programs, indoor pools at Shute Park Aquatic & Recreation Center (Hillsboro), and short nature walks during sunbreaks.

Q: Is parking easy during wet months?

  • A: Downtown has free street parking; parks and trailheads usually have lots. Arrive early on popular weekend mornings.

Best Local Resources

  • National Weather Service (Portland): Daily forecasts, alerts, and rainfall totals.
  • Hillsboro Airport (HIO) weather station: Closest consistent observations for day-to-day planning.
  • ODOT TripCheck: Live cameras and road conditions for US-26, OR-8, and routes to Hagg Lake.
  • City of Cornelius & Clean Water Services: Stormwater tips, leaf collection schedules, and drainage info.
  • Tualatin Valley (visit site): Winery hours, seasonal events, and rainy-day activities.

Summary

  • The Average Rainfall In Cornelius Oregon is about 41 inches per year, with roughly 150 rainy days.
  • Wettest months: November–January. Driest: July–August.
  • Expect light-to-moderate showers, rare snow, and green landscapes most of the year.
  • With good layers and a hooded jacket, Cornelius is easy to enjoy—rain or shine.
  • Best Time to Visit Cornelius (Weather by Month)
  • Cornelius Parks and Trails: What to Expect in Wet Weather
  • Easy Rainy-Day Activities Near Cornelius
  • Driving and Road Tips for TV Highway and US-26 in the Rain