In the south of Peru, May is the first winter month, while in the north, near the Equator, it is a transition month between the hot period that ends in April and the relatively cool period of the following months.
In the east, in the
Amazon forest (see Iquitos, Pucallpa, Puerto Maldonado), May is a
hot, muggy and rainy month, even though in the central-southern part (see Pucallpa, Puerto Maldonado), the rains decrease compared to the previous months.
In the
Andes (see Cajamarca, Cusco, Machu Picchu), where daytime temperatures are stable throughout the year, the period when nocturnal temperatures are lower begins in May, and will last until September. At the highest altitudes it gets cold at night, and especially in the south and above 3,000 meters (9,800 feet), the temperature can drop below freezing (see Cusco, Juliaca). On the other hand, the dry period begins, even in the areas where it rains in summer.
On the
coast, where the climate is arid or desert due to the cool Humboldt Current, May is the last hot and muggy month in the north (see Tumbes), and the last pleasantly warm and sunny in the center-south (see Lima), where fog and cloudy skies will arrive in the following months.
However, in El Niño years, the northern part of the coast, up to the Lambayeque region, becomes hotter and rainier, and when the phenomenon is most intense, it becomes fully tropical, with abundant rains.
A bit of
cool air can arrive in the south, which can bring the night temperature down to about 10 °C (50 °F) both on the coast (see Pisco, Marcona, Ilo) and in the forest (see Puerto Maldonado).
The
sea can still be considered warm enough for swimming in the extreme north (see Tumbes), while in the rest of Peru it is cool or very cool, especially in the stretch from Lima to Marcona, where it drops at about 20 °C (68 °F), because the effects of the Humboldt current are felt more.
However, the sea gets warmer than usual in El Niño years, and cooler in La Niña years.
Peru - Climate data in May| City | Temperature | Rain | Sun | Daylight |
|---|
| (north to south) | Min°C
(°F) | Max°C
(°F) | mm
(in) | Days | Hours | Hours |
|---|
| Tumbes | 22
(72) | 31
(88) | 35
(1.4) | 3 | 6.3 | 12.0 |
|---|
| Iquitos | 22
(72) | 32
(89) | 270
(10.6) | 18 | 5.6 | 11.9 |
|---|
Cajamarca
(2,700 m.) | 7
(44) | 21
(70) | 45
(1.8) | 8 | 6.8 | 11.8 |
|---|
| Trujillo | 17
(63) | 23
(73) | 0
(0) | 0 | 6.5 | 11.7 |
|---|
| Pucallpa | 22
(71) | 32
(90) | 105
(4.1) | 9 | 4.8 | 11.7 |
|---|
| Lima | 17
(63) | 23
(73) | 0
(0) | 1 | 7.8 | 11.5 |
|---|
Puerto Maldonado
(200 m.) | 20
(68) | 30
(86) | 105
(4.1) | 12 | 7.1 | 11.5 |
|---|
Cusco
(3,300 m.) | 4
(39) | 21
(70) | 9
(0.3) | 2 | 7.7 | 11.5 |
|---|
Juliaca
(3,800 m.) | -2
(29) | 18
(64) | 10
(0.4) | 1 | 9.4 | 11.4 |
|---|
Arequipa
(2,300 m.) | 8
(47) | 22
(72) | 0
(0) | 0 | 9.3 | 11.3 |
|---|
See also: Peru, the weather in
April -
JuneThe climate of
Peru