In Aragon, autonomous community and province of Spain, there are the following climatic zones:
- the Pyrenean range in the far north, on the border with France, characterized by an alpine climate (cold mountain climate);
- the pre-Pyrenean range to the north, in valleys or slopes at hill or low-mountain altitudes (see Jaca, Bielsa), where the weather is cold in winter and mild in summer, with some hot days, and relatively abundant rainfall;
- all the center-south, at medium-low altitudes, is characterized by an arid or semi-arid climate, and more or less warm depending on altitude, so we have a transitional Mediterranean (slightly continental) climate in the Ebro Valley (see Zaragoza), with quite mild winters, and hot summers, often torrid, while above 600 metres (2,000 feet), there's a semi-continental climate, similar to that of the central plateau (meseta);
- in the center-south, there is a mountain range as well, called Iberian System (Sistema Ibérico): here the climate becomes colder with increasing altitude, while rain (and snow in winter) becomes more abundant, so that the mountains are covered with forests.



In the far north, on the border with France, we find the chain of the Pyrenees; the highest peak of the entire chain, Pico de Aneto, 3,404 metres (11,168 feet) high, is located in Aragon. Above 2,700 meters (9,000 feet) there are glaciers, which are among the most southern in Europe (together with the small Calderone glacier in Abruzzo, Italy, and the glaciers of Caucasus).
In the Pyrenean area we find the Ordesa y Monte Perdido National Park.
In the area at the foot of the Pyrenees, at the same altitude, the climate is cooler than in the south-central region; in addition this area is exposed to cold air outbreaks, with strong winds, in winter.
In Jaca, located at the foot of the Pyrenees, at 800 metres (2,600 feet) above sea level, the average temperature goes from 2.5 °C (36.5 °F) in January, to 17.5 °C (63.5 °F) in July and August, therefore winter is cold, and sometimes there can be heavy snowfalls. Although the averages are not high, in summer there can be some hot days.
Here are the average temperatures.
Average temperatures - Jaca

Jaca	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Jaca	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-2	-1	1	3	6	9	12	11	10	6	2	-1
Max (°C)	6	8	11	13	16	20	24	24	20	16	10	7
Min (°F)	28	30	34	37	43	48	54	52	50	43	36	30
Max (°F)	43	46	52	55	61	68	75	75	68	61	50	45

In Jaca, 780 millimetres (30.5 inches) of rain or snow fall, well distributed throughout the year, with a maximum in May of 85 mm (3.3 in), and a minimum in July of 45 mm (1.8 in), not very pronounced, since even in summer a few Atlantic fronts can pass, or some thunderstorms can erupt in the afternoon.

In Huesca, located in the center-north, at no great distance from the Pyrenees and at 450 meters (1,475 ft) of altitude, we already enter in the semi-arid zone, with hot summers. Here the average of January is 5 °C (41 °F), that of July and August is 24 °C (75 °F). In winter there can be cold spells, with night frosts, and when the weather is stable, cold and foggy periods may occur; in summer, days with an intense heat are possible, although the air is dry and nights remain cool.
Here are the average temperatures.
Average temperatures - Huesca

Huesca	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Huesca	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	1	2	5	6	10	14	17	17	14	10	5	2
Max (°C)	9	12	16	18	22	28	32	31	26	20	13	9
Min (°F)	34	36	41	43	50	57	63	63	57	50	41	36
Max (°F)	48	54	61	64	72	82	90	88	79	68	55	48

In Huesca, 485 mm (19 in) of rain per year fall, with two maxima in spring and autumn, and quite poor rains, but not entirely absent, in winter (when they are a bit more common but not abundant), and in summer (when rare thunderstorms can break out).
Here is the average precipitation.
Average precipitation - Huesca

Huesca	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Huesca	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	30	30	30	55	55	35	20	30	50	60	50	45	485
Prec. (in)	1.2	1.2	1.2	2.2	2.2	1.4	0.8	1.2	2	2.4	2	1.8	19.1
Days	5	5	4	6	7	4	3	3	5	7	6	6	62

Further to the south, we find Zaragoza, located in the Ebro Valley, 250 meters (820 feet) above sea level, therefore, in the area where the altitude is lower, and the climate can be described as transitional Mediterranean. Here the average temperature goes from 6.5 °C (43.5 °F) in January to 25.5 °C (78 °F) in July and August. In winter, nights are often cold, with possible slight frosts. In summer, hot days are frequent, however, the air is dry, and at night the temperature drops a lot.
Here are the average temperatures.
Average temperatures - Zaragoza

Zaragoza	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Zaragoza	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	3	3	6	8	12	16	18	18	15	11	6	3
Max (°C)	11	13	17	20	24	29	32	32	27	21	15	11
Min (°F)	37	37	43	46	54	61	64	64	59	52	43	37
Max (°F)	52	55	63	68	75	84	90	90	81	70	59	52

In Zaragoza, just 330 mm of precipitation fall annually; winter is particularly dry, given that only 20 mm (0.8 in) of rain fall each month.
Here is the average precipitation.
Average precipitation - Zaragoza

Zaragoza	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Zaragoza	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	20	20	20	40	45	25	20	15	30	35	30	20	330
Prec. (in)	0.8	0.8	0.8	1.6	1.8	1	0.8	0.6	1.2	1.4	1.2	0.8	13
Days	4	4	4	6	7	4	3	2	3	5	5	5	52

The amount of sunshine in Zaragoza is never bad, because some sunny day can occur all year round, although it is better, as happens in Mediterranean climates, in late spring and summer, especially from May to August, when sunny days prevail.
Sunshine - Zaragoza

Zaragoza	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Zaragoza	J	F	M	A	M	J	J	A	S	O	N	D
Sun (hours)	4	6	7	8	9	10	11	10	8	6	5	4

East of Zaragoza we find the Monegros Desert (which is actually a semi-desert zone), where rainfall drops below 300 mm (12 in) per year.



In the center-south of Aragon the altitude rises again for the presence of the mountain chain called Sistema Ibérico, whose highest point is Moncayo (or San Miguel), 2,314 meters (7,592 feet) high.
In Molina de Aragon, at 1,050 metres (3,450 feet), the average temperature goes from 2.5 °C (36.5 °F) in January to 20 °C (68 °F) in July and August. You can notice the cold nights in the winter months, and the wide temperature range in summer, when nights remain very cool.
Here are the average temperatures.
Average temperatures - Molina de A.

Molina de A.	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Molina de A.	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-4	-3	-1	1	5	9	11	11	7	4	0	-3
Max (°C)	9	11	14	16	20	26	30	29	24	18	12	9
Min (°F)	25	27	30	34	41	48	52	52	45	39	32	27
Max (°F)	48	52	57	61	68	79	86	84	75	64	54	48

In Molina de Aragon, average precipitation (rain or snow) amounts to 485 mm (19 in) per year, with a peak in spring, and a small amount in winter.
Here is the average precipitation.
Average precipitation - Molina de A.

Molina de A.	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Molina de A.	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	30	30	30	55	70	50	20	25	50	50	40	40	485
Prec. (in)	1.2	1.2	1.2	2.2	2.8	2	0.8	1	2	2	1.6	1.6	19.1
Days	6	6	6	9	10	7	3	4	5	8	7	7	77

Further to the south-east, in Teruel, capital of the province, 900 meters (2,950 feet) above sea level, the average temperature goes from 3.5 °C (38.5 °F) in January, to 22.5 °C (72.5 °F) in July.
Here are the average temperatures.
Average temperatures - Teruel

Teruel	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Teruel	J	F	M	A	M	J	J	A	S	O	N	D
Min (°C)	-2	-2	1	3	7	11	13	13	10	6	1	-1
Max (°C)	10	12	16	17	22	27	31	31	25	19	13	10
Min (°F)	28	28	34	37	45	52	55	55	50	43	34	30
Max (°F)	50	54	61	63	72	81	88	88	77	66	55	50

In an average year, in Teruel 390 mm (15.3 in) of rain fall. The driest season here is even winter.
Here is the average precipitation.
Average precipitation - Teruel

Teruel	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Teruel	J	F	M	A	M	J	J	A	S	O	N	D	Y
Prec. (mm)	20	15	20	40	60	45	25	40	35	50	25	20	390
Prec. (in)	0.8	0.6	0.8	1.6	2.4	1.8	1	1.6	1.4	2	1	0.8	15.4
Days	4	3	4	7	8	6	3	4	5	6	5	5	59

The best time to visit the Pyrenees and the valleys at the foot of the mountains is summer, being the warmest (or mildest) and the sunniest of the year.
In areas at low altitude of central and southern Aragon (see Huesca, Zaragoza), since the summer is hot, you may prefer spring and autumn (although the rains are more frequent), especially in May, and from mid-September to mid-October.
Those who can stand the heat can choose July and August also in the center-south, but they should be ready to stroll around the cities in hot weather. Given the high temperature range, except perhaps in Zaragoza, even in the center-south in summer it's better to bring a sweatshirt for the evening.