Bostonia weather in May

In May, Bostonia sees average daytime highs of 70°F and overnight lows near 56°F, with 0.4 in of rain across 2 wet days and about 13.7 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 70°F through the month. The sky is clear or mostly clear about 60% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of May to 14 hours by month's end. Set against the rest of the year, May is Bostonia's 7th-clearest and 3rd-windiest month. For the whole year in context, see Bostonia's year-round climate.

Daytime high
70°
6th warmest
Overnight low
56°
7th coldest
Rainfall
0.4 in
2 wet days
Daylight
13 h 42 min
4:54 AM – 6:34 PM
Cloud cover
35%
7th clearest
Wind
5 mph
3rd windiest
Solar energy
7.42 kWh/m²
Travel score
8.2
out of 10

Bostonia is census designated place in San Diego County, California, United States.

Density
3,079/km²
people per km²

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 70°F through the month.

A typical May day in Bostonia reaches about 70°F in the afternoon and slips back to 56°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 63°F and 78°F. Set against its neighbours, May runs about 2°F warmer than April and about 4°F cooler than June.

50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17055
27055
37055
47055
57056
67056
77056
87056
97056
107056
117056
127056
137056
147056
157056
167056
177056
187056
197056
207056
217057
227057
237057
247057
257157
267157
277157
287157
297157
307157
317157

Bostonia weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan64° / 48°2.35.610.16.8
Feb64° / 48°2.9710.86.3
Mar65° / 50°1.95.811.86.8
Apr68° / 53°0.93.912.87.6
May70° / 56°0.4213.78.2
Jun74° / 60°0.10.614.19.2
Jul79° / 64°0.10.713.98.9
Aug81° / 65°0.10.513.28.7
Sep80° / 64°0.20.912.28.8
Oct76° / 59°0.62.511.28.7
Nov70° / 53°0.93.310.37.9
Dec64° / 48°1.95.29.96.8

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 60% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17030
27030
37030
47030
57030
67030
77129
87129
97129
107228
117228
127327
137426
147525
157525
167624
177723
187723
197723
207723
217723
227822
237921
247921
257921
267921
277921
287921
298020
308020
318020

Chance of precipitation in May

Any precipitation

Bostonia gets around 0.4 in of rain over 2 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 7% and peaks near 10% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%151015202531
Rain chance (%)
110
210
310
49
59
69
79
89
99
108
118
128
137
147
157
166
176
186
196
206
215
225
235
244
254
264
274
284
293
303
313

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 74% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
187130
286140
385150
484160
583170
682180
782180
881190
980200
1079210
1178220
1277230
1376240
1475250
1575250
1674260
1774260
1873270
1973270
2071281
2170291
2269301
2368311
2467321
2566331
2665341
2764351
2863361
2963361
3062371
3161381

Wind in May

Winds average 5 mph in May.

Across May, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)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
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 18 min at the start of May to 14 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over May. Sunrise moves from 5:07 AM to 4:46 AM, and sunset from 6:23 PM to 6:45 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:076:23
213.35:066:24
313.35:056:25
413.45:046:26
513.45:036:26
613.45:026:27
713.55:016:28
813.55:006:29
913.54:596:29
1013.54:586:30
1113.64:576:31
1213.64:576:32
1313.64:566:32
1413.64:556:33
1513.74:546:34
1613.74:546:34
1713.74:536:35
1813.74:526:36
1913.84:516:37
2013.84:516:37
2113.84:506:38
2213.84:506:39
2313.84:496:39
2413.94:496:40
2513.94:486:41
2613.94:486:41
2713.94:476:42
2813.94:476:43
2913.94:466:43
3014.04:466:44
3114.04:466:45

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 7.42 kWh/m².

For context, solar energy here swings from a low near 3.14 kWh/m² to a high of 8.08 kWh/m² in June across the year — May's 7.42 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.2Intense
27.2Intense
37.2Intense
47.2Intense
57.2Intense
67.2Intense
77.2Intense
87.3Intense
97.3Intense
107.3Intense
117.3Intense
127.3Intense
137.3Intense
147.4Intense
157.4Intense
167.4Intense
177.4Intense
187.4Intense
197.5Intense
207.5Intense
217.5Intense
227.5Intense
237.6Intense
247.6Intense
257.6Intense
267.6Intense
277.7Intense
287.7Intense
297.7Intense
307.8Intense
317.8Intense
Planning a trip in May

Is May a good time to visit Bostonia?

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

8.2
Sightseeing
6th-best month of the year
5.2
Beach & pool
6th-best month of the year

May is one of the better times to visit Bostonia for general sightseeing.

What to pack for Bostonia in May

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

In May, Bostonia sees daytime highs around 70°F and nights near 56°F. Pack sun protection.

sun protection

Sea temperature near Bostonia in May

The nearest coast averages about 63°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 17 mi away) is warmest in August at about 70°F and coldest in February near 59°F.

It's comfortable for a long swim from Jul 13 to Sep 28 — about 2.6 months when the water holds above 68°F.

60°65°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingcomfortable to swim
Sea temperature (°F)Comfort
Jan60Cool
Feb59Cool
Mar60Cool
Apr61Cool
May63Cool
Jun65Cool
Jul68Refreshing
Aug70Refreshing
Sep69Refreshing
Oct67Cool
Nov64Cool
Dec61Cool

UV index in Bostonia in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bostonia peaks around June 22 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 22UV 11Dec 17UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5High
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Bostonia in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Bostonia is worst in September — around 26 µg/m³ PM2.5 (moderate), about 3.4× the cleanest month (May, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateSep 1625 µg/m³May 168 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb12Moderate
Mar12Moderate
Apr11Good
May8Good
Jun11Good
Jul11Good
Aug15Moderate
Sep26Moderate
Oct14Moderate
Nov12Moderate
Dec16Moderate
Location & terrain

Where is Bostonia?

Bostonia sits at 32.8°N, 116.9°W, 486 ft above sea level, in United States. The nearest listed city is Winter Gardens, 1.9 mi away.

Topography around Bostonia

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Bostonia.

Within 2 miles, the terrain around Bostonia has only modest variations in elevation — a maximum elevation change of 791 ft around an average of 564 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 3,553 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 6,450 ft.

The land around Bostonia is covered by artificial surfaces (78%) within 2 miles, shrubs (34%), artificial surfaces (28%) and trees (21%) within 10 miles, and shrubs (28%) and water (25%) within 50 miles.

2 miles
791 ft
10 miles
3,553 ft
50 miles
6,450 ft
treesshrubsgrasslandartificial surfacesbare terrainwater
May weather nearby: Winter Gardens 1.9 mi · El Cajon 1.9 mi · Santee 3.1 mi · Lakeside 3.7 mi · Casa de Oro-Mount Helix 3.7 mi · Rancho San Diego 4.3 mi · Spring Valley 5.6 mi · La Mesa 5.6 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 Bostonia (32.8075°, -116.9364°, elevation 486 ft), 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).