Latvia Riga Weather in September — Climate Guide
September in Riga is high
September is high for Riga.
September is Riga's best shoulder-season month — daylight still strong (13h+), comfortable 16°C days, crowds at Old Town + Alberta iela dropping 30-40% from August peak, hotels moderating, and the foliage in Mežaparks + along Bastejkalns canal starts to turn mid-month. Sea-temp still 15°C for the brave swimmer. Riga White Night (mid-September, one all-night culture festival with free museum + gallery openings until 02:00) is the canonical autumn cultural event. If you can only travel one shoulder month, September wins over April.
Travel score
Best shoulder month — 13h daylight + foliage starting + Riga White Night
September Weather at a Glance
September averages 61°F / 16°C highs and 48°F / 9°C lows with 70mm precipitation over 12 wet days. Humidity 80%. Sunshine 6h. Daylight drops from 13.5h to 11.5h across the month — sunset moves from 20:00 to 18:45. Sea-temp 15°C still possible swim. Foliage in Mežaparks + Bastejkalns canal peaks mid-to-late month. Cold snap possible late month (occasional first frost).
September Travel Advice
Best shoulder-month for first-time Riga visitors — same daylight as April but at warmer temperatures and full operation. Riga White Night (mid-September, one Saturday — see liveriga.com for exact date) opens museums and galleries free until 02:00 with light installations across Old Town. Compact umbrella + layered clothing essential. Last weekend for Jūrmala beach swimming.
September Pricing Trends
Shoulder pricing returns: Grand Palace $260-420/night, mid-range 4-star $130-220. Flights from major hubs $400-800. Riga White Night weekend adds $30-100 across hotel tiers.
Riga September Weather Stats
Avg High
16°C
Avg Low
9°C
Rainy Days
12
70mm total
Sunshine
6h
Daily avg
Humidity
80%
moderate
UV Index
3
Moderate
Wind
13 km/h
Gusts 34
Sea Temp
15°C
swimming possible (chilly)
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
15 μg/m³
PM10
26 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
16°C
Nighttime
8°C
Humidity and wind affect how the actual temperature feels.
Wind
13 km/h
Max gust 34 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- 16/9°C still comfortable walking + sightseeing
- Crowds dropping 30-40% from August
- Hotels moderating 20-30% off peak
- Riga White Night mid-September (all-night cultural events)
- Last Jūrmala beach weekend (still warm enough)
- Mežaparks autumn foliage starts mid-month
Cons
- Rain 12 days/month + autumn storms possible
- Sunset at 19:20 by month-end (vs 22:15 July)
- Outdoor café season winding down
- Variable weather (cold snap possible late Sept)
- Crayfish season tails off
September Events & Festivals
- Latvian National Day buildup (Nov 18)
- Riga White Night (mid-September — all-night culture festival)
- Last full Jūrmala weekend
- Autumn foliage starts in Mežaparks mid-month
Riga in September — Full Picture
September is Riga's best shoulder-season month — daylight still strong (13h+), comfortable 16°C days, crowds at Old Town + Alberta iela dropping 30-40% from August peak, hotels moderating, and the foliage in Mežaparks + along Bastejkalns canal starts to turn mid-month. Sea-temp still 15°C for the brave swimmer. Riga White Night (mid-September, one all-night culture festival with free museum + gallery openings until 02:00) is the canonical autumn cultural event. If you can only travel one shoulder month, September wins over April.
What to Wear & What to Pack
Early autumn — tee + cardigan or light sweater, light jacket for evenings, sneakers, compact umbrella. Layered approach essential — 16°C days drop to 9°C nights. Sunglasses for low autumn sun.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
10°C
2.3°C
9.3/mo
Summer (Jun·Jul·Aug)
21°C
13°C
10.7/mo
Autumn (Sep·Oct·Nov)
Current10°C
4.7°C
12.3/mo
Winter (Dec·Jan·Feb)
-0.3°C
-5.7°C
10.7/mo
Riga Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| -1° | -7° | 11d·45mm | 1h | 87% | 0 | Quiet | Low season | |
| -1° | -7° | 9d·35mm | 2h | 84% | 1 | Quiet | Low season | |
| 4° | -3° | 10d·35mm | 4h | 78% | 2 | Quiet | Shoulder | |
| 10° | 2° | 9d·40mm | 6h | 72% | 3 | Moderate | Shoulder | |
| May (Best) | 16° | 8° | 9d·45mm | 9h | 68% | 4 | Busy | Peak |
| June (Best) | 20° | 12° | 10d·60mm | 10h | 70% | 5 | Very busy | Peak |
| July (Best) | 22° | 14° | 11d·75mm | 10h | 73% | 5 | Very busy | Peak |
| August (Best) | 21° | 13° | 11d·80mm | 9h | 76% | 4 | Very busy | Peak |
| 16° | 9° | 12d·70mm | 6h | 80% | 3 | Busy | Peak | |
| 10° | 5° | 12d·75mm | 3h | 84% | 2 | Moderate | Shoulder | |
| 4° | 0° | 13d·65mm | 1h | 88% | 1 | Moderate | Shoulder | |
| 1° | -3° | 12d·50mm | 1h | 89% | 0 | Busy | Peak |
View Other Months
Riga September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Riga?
Riga in September is high. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Riga in September?
Riga September averages a high of 16°C and a low of 9°C.
Does it rain much in Riga in September?
Riga September averages 70mm of rainfall over about 12 rainy days.
What should I wear in Riga in September?
Early autumn — tee + cardigan or light sweater, light jacket for evenings, sneakers, compact umbrella. Layered approach essential — 16°C days drop to 9°C nights. Sunglasses for low autumn sun.
What time are sunrise and sunset in Riga in September?
Riga September sunrise is 06:45 and sunset is 19:20, with 12h 35min of daylight.
What's the air quality like in Riga in September?
Riga September air quality (AQI) averages 44, rated Good. PM2.5 averages 15μg/m³.
What activities are recommended in Riga in September?
In September, Riga is great for Riga White Night (mid-September — free overnight cultural events), Mežaparks autumn foliage + Latvian Ethnographic Open-Air Museum, Last Jūrmala beach weekend.
Is September peak season in Riga?
Riga September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Riga
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.