Climate snapshot for alpacas
92/100Alpaca climate comfort score
79°FAverage high, Aug
34°FAverage low, Dec
~2Days above 90°F (32°C) per year
~56Frost nights per year
56 inAnnual precipitation
1Barber pole worm months
17Hay bales / alpaca / year
Main challenges
- Wet ground — 56 in of rain a year — mud, foot problems and fluke habitat
- Low selenium — regional soils and hay tend to be selenium-deficient
Advantages
- Summers rarely reach heat-stress levels for alpacas
- Practically frost-free winters
- Short or no barber pole worm transmission season
- Low meningeal worm risk
Overall rating: 92/100 — Excellent on our alpaca climate comfort score. Climate type: Warm-summer Mediterranean (Köppen Csb).
Month-by-month climate
Average highAverage lowPrecipitation
| Month | High | Low | Precip. | Heat-stress index | Notes |
|---|---|---|---|---|---|
| Jan | 45°F | 35°F | 8.5 in | 123 · ok | — |
| Feb | 48°F | 34°F | 6.3 in | 123 · ok | — |
| Mar | 53°F | 36°F | 6.2 in | 119 · ok | — |
| Apr | 58°F | 39°F | 4.2 in | 122 · ok | grass |
| May | 65°F | 44°F | 2.6 in | 120 · ok | worms, grass |
| Jun | 70°F | 48°F | 1.6 in | 114 · ok | grass |
| Jul | 78°F | 53°F | 0.4 in | 108 · ok | — |
| Aug | 79°F | 53°F | 0.6 in | 122 · caution | — |
| Sep | 73°F | 50°F | 1.8 in | 117 · ok | grass |
| Oct | 61°F | 43°F | 4.8 in | 117 · ok | grass |
| Nov | 50°F | 38°F | 8.5 in | 123 · ok | — |
| Dec | 44°F | 34°F | 10.1 in | 118 · ok | — |
Heat-stress index = average high (°F) + mean humidity (%). “Worms” marks months that suit barber pole worm transmission; “grass” marks the grazing season; “frost” marks months with average lows below freezing. Source: NOAA nClimDiv 1991–2020 county normals.
Alpaca care calendar for Washington County, Oregon
January 45° / 35°F
- Vitamin D for crias and juveniles (ask your vet about product and dose).
- Toenail check and trim.
February 48° / 34°F
- Book your shearer now — spring calendars fill up fast.
- Vitamin D for crias and juveniles (ask your vet about product and dose).
March 53° / 36°F
- CDT boosters for females due next month; prepare a clean birthing paddock and birthing kit.
- Vitamin D for crias and juveniles (ask your vet about product and dose).
- Toenail check and trim.
April 58° / 39°F
- Shearing month: shear the whole herd, and trim toenails, check teeth and body condition while animals are restrained.
- Run pre-season fecal egg counts so you know each animal's baseline.
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Spring grass: switch from hay to pasture gradually over 1–2 weeks and monitor body condition.
May 65° / 44°F
- Barber pole worm season: fecal egg counts every 4–6 weeks, check eyelid color, pick up dung piles twice a week.
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Toenail check and trim.
June 70° / 48°F
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Secure winter hay: about 17 small square bales per alpaca per year here — test a sample before buying.
- Fly season: clean dung piles regularly and use traps around the barn.
July 78° / 53°F
- Cria season: check due dates daily, ensure crias nurse within 4 hours, dip navels and weigh crias daily for two weeks.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Fly season: clean dung piles regularly and use traps around the barn.
- Toenail check and trim.
August 79° / 53°F
- Warm spells possible — watch for open-mouth breathing in heavy-fleeced or dark animals.
- Breeding window for next year's crias (rebreed females 2–4 weeks after birthing).
- Fly season: clean dung piles regularly and use traps around the barn.
September 73° / 50°F
- Fly season: clean dung piles regularly and use traps around the barn.
- Toenail check and trim.
October 61° / 43°F
- Vitamin D for crias and juveniles (ask your vet about product and dose).
November 50° / 38°F
- Vitamin D for crias and juveniles (ask your vet about product and dose).
- Toenail check and trim.
December 44° / 34°F
- Vitamin D for crias and juveniles (ask your vet about product and dose).
Key recommendations
- Shearing: April.
- Best months for crias to be born: Apr–Jul (breed in May–Aug).
- Heat precautions: rarely needed — still provide shade and water.
- Barber pole worm season: May — run fecal egg counts every 4–6 weeks in these months.
- Winter: frost is rare.
- Vitamin D for crias: Oct–Mar.
- Grazing season: Apr–Jun, Sep–Oct (about 5 months); feed hay the rest of the year.
- Meningeal worm: Meningeal worm is not established in this region.
- Selenium: Soils and hay in this state are often selenium-deficient. Use a camelid mineral formulated for low-selenium areas and blood-test a few animals each year.
Tools: heat-stress calculator · winter hay calculator · due-date calculator · parasite control guide.
Alpaca farms & shops nearby
Places mapped on OpenStreetMap with “alpaca” in their name, within about 80 km (50 miles). Contact them before visiting — opening times change.
| Name | Type | Distance | Website |
|---|---|---|---|
| Stoneberg Alpacas | activity | 9 mi | Visit |
| Alpacas of Tualatin Valley | farm | 11 mi | Visit |
| The Alpaca Group | farm | 28 mi | — |
| Columbia Mist Alpacas | farm | 32 mi | — |
Data © OpenStreetMap contributors. Know a farm that's missing? Add it to OpenStreetMap and it will appear here in the next update.
Frequently asked questions
Can you raise alpacas in Washington County, Oregon?
Yes. Alpacas are kept successfully in most climates with good management. Washington County, Oregon scores 92/100 (excellent) on our alpaca climate comfort scale; the key issues are wet ground and low selenium.
When should alpacas be shorn in Washington County, Oregon?
Plan shearing for April, once nights stay above about 38°F (3°C) but before summer heat builds.
What is the best time for crias to be born in Washington County, Oregon?
Mild months suit newborn crias best — here that is Apr–Jul. For births then, breed females in May–Aug (gestation is about 335 days).
How much hay does an alpaca need per year in Washington County, Oregon?
With roughly 7 months of little or no grazing, plan on about 833 lb (378 kg) — around 17 small square bales — per adult alpaca per year, plus waste.
Nearby counties
Coordinates 45.554, -123.098 · land area 724 sq mi. Long-term averages, not forecasts. See methodology and data sources. Back to Oregon.