Senec weather in April

In April, Senec sees average daytime highs of 17°C and overnight lows near 6°C, with 42 mm of precipitation across 8 wet days and about 13.4 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 14°C in the first days to 19°C by the end. The sky is clear or mostly clear about 31% of the time in April, and the air most often feels dry.

Daylight stretches from about 12 h 30 min at the start of April to 14 h 12 min by month's end. Set against the rest of the year, April is Senec's 5th-clearest and 3rd-windiest month. For the whole year in context, see Senec's year-round climate.

Daytime high: 17°; 6th warmest
Overnight low: 6°; 6th coldest
Precipitation: 42 mm; 8 wet days
Daylight: 13 h 24 min; 5:08 AM – 6:33 PM
Cloud cover: 58%; 5th clearest
Wind: 13 km/h; 3rd windiest
Solar energy: 4.77 kWh/m²
Travel score: 5.4; out of 10

Senec is town in Slovakia.

Density: 520/km²; people per km²
Founded: 1251

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

← March Senec year-round climate May →Best places to visit in April

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in April

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 14°C in the first days to 19°C by the end.

A typical April day in Senec reaches about 17°C in the afternoon and slips back to 6°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 23°C. Set against its neighbours, April runs about 6°C warmer than March and about 5°C cooler than May.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	14	14	14	14	14	15	15	15	15	15	15	16	16	16	16	16	17	17	17	18	18	18	18	19	19	19	19	20	20	20
Avg low (°C)	4	4	4	4	5	5	5	5	5	5	5	5	6	6	6	6	6	6	7	7	7	7	8	8	8	8	8	9	9	9

	Avg high (°C)	Avg low (°C)
1	14	4
2	14	4
3	14	4
4	14	4
5	14	5
6	15	5
7	15	5
8	15	5
9	15	5
10	15	5
11	15	5
12	16	5
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	7
20	18	7
21	18	7
22	18	7
23	18	8
24	19	8
25	19	8
26	19	8
27	19	8
28	20	9
29	20	9
30	20	9

How April really feels in Senec

Once humidity and wind are folded in, April averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

April sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Senec weather by month

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

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	3° / -3°	36	8	3.9	8.6	0.0
Feb	5° / -1°	33	7.9	3.2	9.9	0.3
Mar	11° / 2°	40	8.4	1.6	11.6	2.6
Apr	17° / 6°	42	8	0.3	13.4	5.4
May	21° / 11°	67	10.7	0	14.9	6.4
Jun	25° / 14°	72	10.8	0	15.8	6.7
Jul	27° / 16°	74	11	0	15.5	6.4
Aug	27° / 16°	64	9.4	0	14.1	6.7
Sep	22° / 12°	64	8.6	0	12.4	6.8
Oct	15° / 7°	48	8.6	0.1	10.6	4.8
Nov	9° / 3°	47	8.8	1.6	9	1.7
Dec	3° / -1°	41	8.7	2.9	8.2	0.0

Cloud cover in April

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in April.

Beyond those clear spells, partly cloudy skies cover about 16% of April, with mostly cloudy or overcast conditions the remaining 53%. Skies tend to open up as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	43	43	44	44	44	44	44	43	43	42	42	42	43	44	44	46	46	47	48	49	49	51	52	52	53	53	53	52	52	52
Cloudier (%)	57	57	56	56	56	56	56	57	57	58	58	58	57	56	56	54	54	53	52	51	51	49	48	48	47	47	47	48	48	48

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	44	56
4	44	56
5	44	56
6	44	56
7	44	56
8	43	57
9	43	57
10	42	58
11	42	58
12	42	58
13	43	57
14	44	56
15	44	56
16	46	54
17	46	54
18	47	53
19	48	52
20	49	51
21	49	51
22	51	49
23	52	48
24	52	48
25	53	47
26	53	47
27	53	47
28	52	48
29	52	48
30	52	48

Chance of precipitation in April

Any precipitationSnow

Senec gets around 42 mm of rain and snow over 8 wet days in April. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 28% and peaks near 31% on the wettest days, and about 0 day brings snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	27	27	27	27	27	27	27	27	27	27	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	29	29	30	31	31
Snow chance (%)	3	3	2	2	2	2	2	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	1	0	0	0	0	0	0

	Rain chance (%)	Snow chance (%)
1	27	3
2	27	3
3	27	2
4	27	2
5	27	2
6	27	2
7	27	2
8	27	1
9	27	1
10	27	1
11	28	1
12	28	1
13	28	1
14	28	1
15	28	1
16	28	1
17	28	1
18	28	1
19	28	1
20	28	1
21	28	1
22	28	1
23	28	1
24	28	1
25	28	0
26	29	0
27	29	0
28	30	0
29	31	0
30	31	0

Humidity in April

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, April lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	99	99	99	98	98	97	97	96
Comfortable (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1	1	2	2	3	3	4

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	99	1
24	99	1
25	99	1
26	98	2
27	98	2
28	97	3
29	97	3
30	96	4

Wind in April

Winds average 13 km/h in April.

Across April, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	13	13	13	13	13	13	13	13	13	13	13	13	13	13	13	13	12	12	12	12	12	12	12	12	12	12	12	12	12	12
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	13	light breeze
2	13	light breeze
3	13	light breeze
4	13	light breeze
5	13	light breeze
6	13	light breeze
7	13	light breeze
8	13	light breeze
9	13	light breeze
10	13	light breeze
11	13	light breeze
12	13	light breeze
13	13	light breeze
14	13	light breeze
15	13	light breeze
16	13	light breeze
17	12	light breeze
18	12	light breeze
19	12	light breeze
20	12	light breeze
21	12	light breeze
22	12	light breeze
23	12	light breeze
24	12	calm
25	12	calm
26	12	calm
27	12	calm
28	12	calm
29	12	calm
30	12	calm

Sunrise & sunset in April

DaylightNight

Daylight runs from about 12 h 30 min at the start of April to 14 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 102 minutes over April. Sunrise moves from 5:39 AM to 4:42 AM, and sunset from 6:11 PM to 6:53 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.5	12.6	12.6	12.7	12.8	12.8	12.9	12.9	13.0	13.1	13.1	13.2	13.2	13.3	13.4	13.4	13.5	13.5	13.6	13.6	13.7	13.8	13.8	13.9	13.9	14.0	14.0	14.1	14.1	14.2
Sunrise (AM)	5:39	5:37	5:35	5:33	5:31	5:29	5:27	5:25	5:23	5:20	5:18	5:16	5:14	5:12	5:10	5:08	5:06	5:04	5:02	5:00	4:59	4:57	4:55	4:53	4:51	4:49	4:47	4:46	4:44	4:42
Sunset (PM)	6:11	6:12	6:14	6:15	6:17	6:18	6:20	6:21	6:23	6:24	6:26	6:27	6:29	6:30	6:31	6:33	6:34	6:36	6:37	6:39	6:40	6:42	6:43	6:45	6:46	6:48	6:49	6:51	6:52	6:53

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.5	5:39	6:11
2	12.6	5:37	6:12
3	12.6	5:35	6:14
4	12.7	5:33	6:15
5	12.8	5:31	6:17
6	12.8	5:29	6:18
7	12.9	5:27	6:20
8	12.9	5:25	6:21
9	13.0	5:23	6:23
10	13.1	5:20	6:24
11	13.1	5:18	6:26
12	13.2	5:16	6:27
13	13.2	5:14	6:29
14	13.3	5:12	6:30
15	13.4	5:10	6:31
16	13.4	5:08	6:33
17	13.5	5:06	6:34
18	13.5	5:04	6:36
19	13.6	5:02	6:37
20	13.6	5:00	6:39
21	13.7	4:59	6:40
22	13.8	4:57	6:42
23	13.8	4:55	6:43
24	13.9	4:53	6:45
25	13.9	4:51	6:46
26	14.0	4:49	6:48
27	14.0	4:47	6:49
28	14.1	4:46	6:51
29	14.1	4:44	6:52
30	14.2	4:42	6:53

Solar energy in April

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in April, about 4.77 kWh/m².

For context, solar energy here swings from a low near 0.87 kWh/m² to a high of 5.87 kWh/m² in June across the year — April's 4.77 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	4.0	4.1	4.1	4.2	4.2	4.3	4.3	4.3	4.4	4.5	4.5	4.5	4.6	4.7	4.7	4.8	4.8	4.9	4.9	5.0	5.0	5.1	5.1	5.2	5.2	5.2	5.2	5.3	5.3	5.3
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	4.0	Bright
2	4.1	Bright
3	4.1	Bright
4	4.2	Bright
5	4.2	Bright
6	4.3	Bright
7	4.3	Bright
8	4.3	Bright
9	4.4	Bright
10	4.5	Bright
11	4.5	Bright
12	4.5	Bright
13	4.6	Bright
14	4.7	Bright
15	4.7	Bright
16	4.8	Bright
17	4.8	Bright
18	4.9	Bright
19	4.9	Bright
20	5.0	Bright
21	5.0	Bright
22	5.1	Bright
23	5.1	Bright
24	5.2	Bright
25	5.2	Bright
26	5.2	Bright
27	5.2	Bright
28	5.3	Bright
29	5.3	Bright
30	5.3	Bright

Planning a trip in April

Is April a good time to visit Senec?

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

5.4

Sightseeing

6th-best month of the year

1.2

Beach & pool

6th-best month of the year

April is a reasonable time to visit Senec for sightseeing.

What to pack for Senec in April

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

In April, Senec sees daytime highs around 17°C and nights near 6°C. Worth packing: a warm layer, rain gear and sun protection. About 8 days see rain.

a warm layerrain gearsun protection

UV index in Senec in April

LowModerateHighVery highExtreme

Clear-sky midday UV in April peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Senec peaks around July 11 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	1	2	4	6	6	7	8	6	4	3	1	1
Level	Low	Low	Moderate	High	High	Very high	Very high	High	Moderate	Moderate	Low	Low

	UV index (midday)	Level
Jan	1	Low
Feb	2	Low
Mar	4	Moderate
Apr	6	High
May	6	High
Jun	7	Very high
Jul	8	Very high
Aug	6	High
Sep	4	Moderate
Oct	3	Moderate
Nov	1	Low
Dec	1	Low

Air quality in Senec in April

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Senec is worst in June — around 17 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	13	13	16	16	16	17	15	15	13	12	12	11
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good	Good

	PM2.5 (µg/m³)	Level
Jan	13	Moderate
Feb	13	Moderate
Mar	16	Moderate
Apr	16	Moderate
May	16	Moderate
Jun	17	Moderate
Jul	15	Moderate
Aug	15	Moderate
Sep	13	Moderate
Oct	12	Moderate
Nov	12	Good
Dec	11	Good

Location & terrain

Where is Senec?

Senec sits at 48.2°N, 17.4°E, 127 m above sea level, in Slovakia. The nearest listed city is Pezinok, 13 km away.

Topography around Senec

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

Within 3 km, the terrain around Senec has only modest variations in elevation — a maximum elevation change of 50 m around an average of 129 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 289 m; within 80 km, large variations in elevation — a maximum elevation change of 951 m.

The land around Senec is covered by cropland (56%) and artificial surfaces (20%) within 3 km, cropland (68%) within 16 km, and cropland (57%) and trees (25%) within 80 km.

3 km

50 m

cropland 56%

16 km

289 m

cropland 68%

80 km

951 m

cropland 57%

treesgrasslandcroplandartificial surfaceswaterwetland

← March Senec year-round climate May →Best places to visit in April

April weather nearby: Pezinok 13 km · Vrakuňa 17 km · Podunajské Biskupice 17 km · Trnava 22 km · Petržalka 23 km · Bratislava 23 km · Staré Mesto 24 km · Galanta 24 km

Slovakia travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type C / E / F; 230 V · 50 Hz
Prices: ≈ 58% of US; price level, 2025
GDP per capita: $28,544; 2025
Happiness: 6.3 / 10; World Happiness, 2025
Safe drinking water: 100%; of population, 2024
Homicide rate: 1.1; per 100k, 2023
Road deaths: 6.1; per 100k/yr, 2019
Income group: High; World Bank
English: Very high; EF EPI 606
Religion

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 Senec (48.2195°, 17.4004°, elevation 127 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. 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).

	Avg high (°C)	Avg low (°C)
1	14	4
2	14	4
3	14	4
4	14	4
5	14	5
6	15	5
7	15	5
8	15	5
9	15	5
10	15	5
11	15	5
12	16	5
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	7
20	18	7
21	18	7
22	18	7
23	18	8
24	19	8
25	19	8
26	19	8
27	19	8
28	20	9
29	20	9
30	20	9

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	44	56
4	44	56
5	44	56
6	44	56
7	44	56
8	43	57
9	43	57
10	42	58
11	42	58
12	42	58
13	43	57
14	44	56
15	44	56
16	46	54
17	46	54
18	47	53
19	48	52
20	49	51
21	49	51
22	51	49
23	52	48
24	52	48
25	53	47
26	53	47
27	53	47
28	52	48
29	52	48
30	52	48

	Rain chance (%)	Snow chance (%)
1	27	3
2	27	3
3	27	2
4	27	2
5	27	2
6	27	2
7	27	2
8	27	1
9	27	1
10	27	1
11	28	1
12	28	1
13	28	1
14	28	1
15	28	1
16	28	1
17	28	1
18	28	1
19	28	1
20	28	1
21	28	1
22	28	1
23	28	1
24	28	1
25	28	0
26	29	0
27	29	0
28	30	0
29	31	0
30	31	0

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	99	1
24	99	1
25	99	1
26	98	2
27	98	2
28	97	3
29	97	3
30	96	4

	Avg high (°C)	Avg low (°C)
1	14	4
2	14	4
3	14	4
4	14	4
5	14	5
6	15	5
7	15	5
8	15	5
9	15	5
10	15	5
11	15	5
12	16	5
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	7
20	18	7
21	18	7
22	18	7
23	18	8
24	19	8
25	19	8
26	19	8
27	19	8
28	20	9
29	20	9
30	20	9

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	44	56
4	44	56
5	44	56
6	44	56
7	44	56
8	43	57
9	43	57
10	42	58
11	42	58
12	42	58
13	43	57
14	44	56
15	44	56
16	46	54
17	46	54
18	47	53
19	48	52
20	49	51
21	49	51
22	51	49
23	52	48
24	52	48
25	53	47
26	53	47
27	53	47
28	52	48
29	52	48
30	52	48

	Rain chance (%)	Snow chance (%)
1	27	3
2	27	3
3	27	2
4	27	2
5	27	2
6	27	2
7	27	2
8	27	1
9	27	1
10	27	1
11	28	1
12	28	1
13	28	1
14	28	1
15	28	1
16	28	1
17	28	1
18	28	1
19	28	1
20	28	1
21	28	1
22	28	1
23	28	1
24	28	1
25	28	0
26	29	0
27	29	0
28	30	0
29	31	0
30	31	0

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	99	1
24	99	1
25	99	1
26	98	2
27	98	2
28	97	3
29	97	3
30	96	4

	Avg high (°C)	Avg low (°C)
1	14	4
2	14	4
3	14	4
4	14	4
5	14	5
6	15	5
7	15	5
8	15	5
9	15	5
10	15	5
11	15	5
12	16	5
13	16	6
14	16	6
15	16	6
16	16	6
17	17	6
18	17	6
19	17	7
20	18	7
21	18	7
22	18	7
23	18	8
24	19	8
25	19	8
26	19	8
27	19	8
28	20	9
29	20	9
30	20	9

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	44	56
4	44	56
5	44	56
6	44	56
7	44	56
8	43	57
9	43	57
10	42	58
11	42	58
12	42	58
13	43	57
14	44	56
15	44	56
16	46	54
17	46	54
18	47	53
19	48	52
20	49	51
21	49	51
22	51	49
23	52	48
24	52	48
25	53	47
26	53	47
27	53	47
28	52	48
29	52	48
30	52	48

	Rain chance (%)	Snow chance (%)
1	27	3
2	27	3
3	27	2
4	27	2
5	27	2
6	27	2
7	27	2
8	27	1
9	27	1
10	27	1
11	28	1
12	28	1
13	28	1
14	28	1
15	28	1
16	28	1
17	28	1
18	28	1
19	28	1
20	28	1
21	28	1
22	28	1
23	28	1
24	28	1
25	28	0
26	29	0
27	29	0
28	30	0
29	31	0
30	31	0

	Dry (%)	Comfortable (%)
1	100	0
2	100	0
3	100	0
4	100	0
5	100	0
6	100	0
7	100	0
8	100	0
9	100	0
10	100	0
11	100	0
12	100	0
13	100	0
14	100	0
15	100	0
16	100	0
17	100	0
18	100	0
19	100	0
20	100	0
21	100	0
22	100	0
23	99	1
24	99	1
25	99	1
26	98	2
27	98	2
28	97	3
29	97	3
30	96	4