Imperial weather in September

In September, Imperial sees average daytime highs of 21°C and overnight lows near 15°C, with 0 mm of rain across 0.1 wet days and about 11.9 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 21°C through the month. The sky is clear or mostly clear about 73% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 42 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Imperial's 4th-clearest and 5th-windiest month. For the whole year in context, see Imperial's year-round climate.

Daytime high
21°
9th warmest
Overnight low
15°
3rd coldest
Rainfall
0 mm
0.1 wet days
Daylight
11 h 54 min
6:02 AM – 5:58 PM
Cloud cover
28%
4th clearest
Wind
5 km/h
5th windiest
Solar energy
6.88 kWh/m²
Travel score
8.6
out of 10

Imperial is city in Lima, Peru.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 21°C through the month.

A typical September day in Imperial reaches about 21°C in the afternoon and slips back to 15°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 23°C. Set against its neighbours, September runs on par with August and on par with October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
12115
22115
32115
42115
52115
62115
72115
82115
92115
102115
112115
122115
132115
142115
152115
162115
172115
182115
192115
202115
212115
222115
232115
242115
252115
262215
272215
282215
292215
302215

Imperial weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan24° / 18°278.212.76.7
Feb24° / 19°4411.712.46.0
Mar24° / 19°267.512.16.8
Apr24° / 18°41.411.78.2
May23° / 16°10.411.48.8
Jun21° / 16°00.111.28.7
Jul21° / 15°10.111.38.7
Aug21° / 15°0011.68.7
Sep21° / 15°00.111.98.6
Oct22° / 15°30.812.38.2
Nov23° / 16°20.412.68.1
Dec23° / 17°72.112.87.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 73% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 15%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1919
2919
3919
4919
58911
68911
78911
88812
98713
108713
118614
128614
138515
148515
158515
168515
178416
188317
198317
208317
218317
228218
238218
248218
258119
268119
278119
288119
298119
308119

Chance of precipitation in September

Any precipitation

Imperial gets around 0 mm of rain over 0.1 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 0% and peaks near 1% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
231
241
251
261
271
281
291
301

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 84% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
19010
29010
38911
48911
58911
68812
78812
88812
98713
108713
118614
128614
138515
148515
158416
168416
178317
188317
198218
208218
218119
228020
238020
247921
257921
267921
277822
287822
297822
307723

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 42 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 24 minutes over September. Sunrise moves from 6:13 AM to 5:52 AM, and sunset from 5:57 PM to 5:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.76:135:57
211.86:125:57
311.86:115:58
411.86:115:58
511.86:105:58
611.86:095:58
711.86:095:58
811.86:085:58
911.86:075:58
1011.96:065:58
1111.96:065:58
1211.96:055:58
1311.96:045:58
1411.96:035:58
1511.96:035:58
1611.96:025:58
1711.96:015:58
1812.06:005:58
1912.06:005:58
2012.05:595:58
2112.05:585:58
2212.05:575:58
2312.05:575:58
2412.05:565:58
2512.05:555:58
2612.15:545:58
2712.15:545:58
2812.15:535:58
2912.15:525:58
3012.15:525:58

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.88 kWh/m².

For context, solar energy here swings from a low near 5.28 kWh/m² to a high of 7.33 kWh/m² in November across the year — September's 6.88 kWh/m² sits near the top of that range.

02468151015202530
Solar energy (kWh/m²)Level
16.6Intense
26.6Intense
36.7Intense
46.7Intense
56.7Intense
66.7Intense
76.7Intense
86.8Intense
96.8Intense
106.8Intense
116.8Intense
126.8Intense
136.8Intense
146.9Intense
156.9Intense
166.9Intense
176.9Intense
186.9Intense
196.9Intense
207.0Intense
217.0Intense
227.0Intense
237.0Intense
247.0Intense
257.0Intense
267.1Intense
277.1Intense
287.1Intense
297.1Intense
307.1Intense
Planning a trip in September

Is September a good time to visit Imperial?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

8.6
Sightseeing
5th-best month of the year
5.4
Beach & pool
9th-best month of the year

September is one of the better times to visit Imperial for general sightseeing.

What to pack for Imperial in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Imperial sees daytime highs around 21°C and nights near 15°C. Pack sun protection.

sun protection

Sea temperature near Imperial in September

The nearest coast averages about 17°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in February at about 21°C and coldest in September near 17°C.

It's comfortable for a long swim from Jan 1 to Apr 21 — about 3.6 months when the water holds above 20°C.

16°18°20°22°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb21Refreshing
Mar21Refreshing
Apr20Refreshing
May19Cool
Jun18Cool
Jul18Cool
Aug17Cool
Sep17Cool
Oct17Cool
Nov18Cool
Dec19Cool

UV index in Imperial in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Imperial peaks around February 12 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 22 at about 8 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 12UV 16Jun 22UV 8
UV index (midday)Level
Jan15Extreme
Feb16Extreme
Mar13Extreme
Apr12Extreme
May10Very high
Jun8Very high
Jul8Very high
Aug10Extreme
Sep11Extreme
Oct13Extreme
Nov13Extreme
Dec14Extreme
Location & terrain

Where is Imperial?

Imperial sits at 13.1°S, 76.4°W, 91 m above sea level, in Peru. The nearest listed city is San Vicente de Cañete, 4.0 km away.

Topography around Imperial

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Imperial.

Within 3 km, the terrain around Imperial has only modest variations in elevation — a maximum elevation change of 168 m around an average of 98 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,426 m; within 80 km, extreme variations in elevation — a maximum elevation change of 5,195 m.

The land around Imperial is covered by cropland (42%) and bare terrain (22%) within 3 km, bare terrain (48%) within 16 km, and bare terrain (38%) and water (32%) within 80 km.

3 km
168 m
16 km
1,426 m
80 km
5,195 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: San Vicente de Cañete 4.0 km · Nuevo Imperial 4.0 km · Chincha Alta 46 km · Mala 54 km · San Clemente 71 km · Pisco 74 km · Paracas 90 km · Villa Poeta José Gálvez Barrenechea 112 km

Peru travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B / C
220 V · 60 Hz
Prices
≈ 51% of US
price level, 2025
GDP per capita
$9,684
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
49%
of population, 2024
Homicide rate
8.6
per 100k, 2021
Road deaths
13.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 519
Religion
Catholic 76%Evangelical Christian 16%no religion 5%other religions 3%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Imperial (-13.0593°, -76.3527°, elevation 91 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).