Map from Google - Navarre

In Navarre, an autonomous community and province of Spain, there are the following climatic zones:
- in the north-west, we find an area influenced by the Atlantic Ocean, cool and humid, occupied by hills and low mountains, belonging to the Cantabrian relief, and by green valleys;
- in the north-east, the Pyrenean area, along the border with France, cold due to altitude, which receives snowfalls in winter and thunderstorms in summer;
- in the central part, an intermediate zone, slightly continental and moderately rainy, where the capital Pamplona is located;
- in the south, an arid area, with slightly cold winters and hot summers. Here we find also a practically flat area: in the Ebro Valley, the altitude drops below 300 metres (1,000 feet).

The rains are abundant in the north, where they exceed 1,500 millimetres (60 inches) per year, and in some cases even 2,000 mm (80 in), while they become progressively more scarce as you head south. Pamplona is located in the intermediate band, where precipitation ranges from 700 to 1,000 mm (27 to 40 in) per year. In the south, precipitation drops below 600 mm (23.5 in), and in the southernmost part, which is definitely arid (see Tudela), even below 400 mm (16 in).

Let's start from the north, the area affected by the Atlantic Ocean. In the valleys located at low altitude, around sea level, winter is mild and summer is pleasantly warm.
Here are for example the average temperatures of Lesaka.
Average temperatures - Lesaka
LesakaJanFebMarAprMayJunJulAugSepOctNovDec
LesakaJFMAMJJASOND
Min (°C)345710131516131174
Max (°C)121316182124262625211513
Min (°F)373941455055596155524539
Max (°F)545561647075797977705955

In Lesaka the rains are plentiful, since they reach 1.750 mm (69 in), and are frequent throughout the year. Summer is the least rainy season.
Here is the average precipitation in Lesaka.
Average precipitation - Lesaka
LesakaJanFebMarAprMayJunJulAugSepOctNovDecYear
LesakaJFMAMJJASONDY
Prec. (mm)1901551551651459070901151552201951745
Prec. (in)7.56.16.16.55.73.52.83.54.56.18.77.768.7
Days141313161512111211131514157

At higher altitudes, both in the Cantabrian area and in the Pyrenees, the temperature decreases. The highest point of Navarra is Mesa de los Tres Reyes, 2,428 metres (7,966 feet) high, on the border with France.
Here for example the average temperatures of Abaurregaina/Abaurrea Alta, situated at 1,050 metres (3,450 ft), in the northeast, in the Pyrenean area.
Average temperatures - Abaurregaina
AbaurregainaJanFebMarAprMayJunJulAugSepOctNovDec
AbaurregainaJFMAMJJASOND
Min (°C)-1-102691111962-1
Max (°C)67101116202324201597
Min (°F)303032364348525248433630
Max (°F)434550526168737568594845

In Abaurregaina, 1,050 mm (41.5 in) of rain or snow per year fall, with a minimum in August, of 65 mm (2.6 in) and a maximum in November, of 180 mm (7 in). There are on average 126 days with rain and 26 days with snow per year; snowfall usually occurs from November to April.

Pamplona, Plaza del Castillo

We now come to the central belt.
In the capital Pamplona, winter is cold enough: the average temperature in January is 5 °C (41 °F). There are mild periods, in which daytime temperatures hover about 12/15 °C (54/59 °F), but the city is exposed to cold air outbreaks from Eastern Europe, associated with snowfalls and frosts: there are on average 10 days with snow per year. In January 1985, the temperature dropped to -15 °C (5 °F).
Summer is warm enough, the average of August being 21.5 °C (70.5 °F), generally with cool nights, but the temperature undergoes considerable variations, both between night and day and from one day to another: waves of intense heat are possible, in which the temperature can exceed 35 °C (95 °F), and sometimes can reach as high as 40 °C (104 °F), but also pleasant and spring-like days, with highs around 20 °C (68 °F), in which nights can be very cool, below 10 °C (50 °F), especially in June.
Here are the average temperatures.
Average temperatures - Pamplona
PamplonaJanFebMarAprMayJunJulAugSepOctNovDec
PamplonaJFMAMJJASOND
Min (°C)1245912141512952
Max (°C)91115162125282825191310
Min (°F)343639414854575954484136
Max (°F)485259617077828277665550

In Pamplona, 700 mm (27.5 in) of rain (or snow) per year fall. The wettest seasons are spring and autumn; summer is the least rainy season, but it is not so dry, since occasionally some rains or thunderstorms can occur.
Here is the average precipitation.
Average precipitation - Pamplona
PamplonaJanFebMarAprMayJunJulAugSepOctNovDecYear
PamplonaJFMAMJJASONDY
Prec. (mm)605055756045354045757575700
Prec. (in)2.422.232.41.81.41.61.833327.6
Days1098101064569101197

Bardenas Reales

We come now to the south. Here the summer becomes hot, and the rains become much more scarce, so much so that there is also a semi-desert area, with a lunar landscape, called Bardenas Reales.
Here are the average temperatures of Tudela, located in the Ebro Valley. In summer, hot days, with highs around or above 35 °C (95 °F), are quite frequent.
Average temperatures - Tudela
TudelaJanFebMarAprMayJunJulAugSepOctNovDec
TudelaJFMAMJJASOND
Min (°C)235811151717141163
Max (°C)101216192328313126201410
Min (°F)363741465259636357524337
Max (°F)505461667382888879685750

In Tudela, precipitation amounts to only 380 mm (15 in) per year; on average it does not reach 50 mm (2 in) in any month, and winter is particularly dry, while in summer some thunderstorms can occasionally break out.
Here is the average precipitation.
Average precipitation - Tudela
TudelaJanFebMarAprMayJunJulAugSepOctNovDecYear
TudelaJFMAMJJASONDY
Prec. (mm)252025404535202540453530380
Prec. (in)10.811.61.81.40.811.61.81.41.215
Days9689974571010891

The amount of sunshine in Navarre is not very good in the north, as cloudy days are frequent throughout the year (although in summer it gets to 7/8 hours of sunshine per day), and becomes good in summer in Pamplona (where there are 10 hours of sunshine per day in July), and even more in the south, where sunny days are frequent throughout the year, but especially in summer.
Here are the average sunshine hours per day in Pamplona.
Sunshine - Pamplona
PamplonaJanFebMarAprMayJunJulAugSepOctNovDec
PamplonaJFMAMJJASOND
Sun (hours)3466791097543

When to go

The best time to visit Navarre, at least in the north, is the summer, from June to August or the first half of September, being the driest and sunniest. July and August are the warmest and least rainy months. You must take into account some rain in midsummer as well, and some nights a little cool in the valleys, and a little cold in hill areas.
In Pamplona, in July and August you can find a warm weather during the day, with cool nights, but there are also hot days, so you may prefer June and September.
The south, since in summer can be hot, can be visited in spring and autumn, especially in May, and from mid-September to mid-October, even though it rains more often.