(according to the Köppen classification: humid subtropical climate - Cfa), with mild winters (from June to August) and hot summers (from December to March). The rains are well distributed throughout the year.
The city is located in the east of Uruguay, at 33 degrees south latitude, on the banks of the Olimar Grande River, 80 km (50 mi) from the border with Brazil and 110 km (68 mi) from the Atlantic Ocean coast.
all year round, in fact the heat records are around 30 °C (86 °F) even in winter. Instead, from December to March, in summer, there can be heat waves, in which the temperature reaches 38/39 °C (100/102 °F). However, the south wind is able to interrupt the hot and sultry periods, bringing pleasant (and sometimes very cool) weather for two or three days.
from the south, during which the temperature can drop to the freezing point or a little below at night, and can remain around 10 °C (50 °F) during the day. Also, fog can sometimes form.
To visit Treinta y Tres you can choose spring and autumn (in particular, the months of October and April), even though they are quite rainy seasons.
If you want you can also choose the summer, since the city is mitigated by the ocean, however, sometimes it can get very hot. Even in the height of summer, it is advisable to bring a sweatshirt for cooler evenings.
However, the winter is not a prohibitive season, and it rarely gets very cold.
. Here are the average temperatures.
January, the warmest month of the year, is generally a warm to hot month. The average temperature is of
24.3 °C, with a minimum of
17.9 °C and a maximum of
30.6 °C.

On the coldest nights of the month, the temperature usually drops to around
10 °C. However, it dropped to
7.4 °C in January 1992.

On the warmest days of the month, the temperature usually reaches around
36 °C. However, it reached
39 °C in January 2006.

Precipitation amounts to
105 mm, distributed over 6 days.
The day lasts on average 14 hours and 0 minutes.

There are on average 8.5 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 68%.
The average wind speed is of
8.6 kph.
February is generally a warm to hot, muggy month. The average temperature is of
23.4 °C, with a minimum of
17.5 °C and a maximum of
29.4 °C.

On the coldest nights of the month, the temperature usually drops to around
9.5 °C. However, it dropped to
7.4 °C in February 2001.

On the warmest days of the month, the temperature usually reaches around
35.5 °C. However, it reached
38.1 °C in February 1991.

Precipitation amounts to
130 mm, distributed over 7 days.
The day lasts on average 13 hours and 10 minutes.

There are on average 7.5 hours of sunshine per day. So, the sun shines 58% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is of
8.4 kph.
March is generally a warm month. The average temperature is of
22.2 °C, with a minimum of
16.3 °C and a maximum of
28.1 °C.

On the coldest nights of the month, the temperature usually drops to around
8.5 °C. However, it dropped to
4.7 °C in March 1995.

On the warmest days of the month, the temperature usually reaches around
33.5 °C. However, it reached
39 °C in March 2005.

Precipitation amounts to
110 mm, distributed over 5 days.
The day lasts on average 12 hours and 10 minutes.

There are on average 7 hours of sunshine per day. So, the sun shines 58% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is of
7.1 kph.
April is generally a warm month. The average temperature is of
18.7 °C, with a minimum of
13.1 °C and a maximum of
24.2 °C.

On the coldest nights of the month, the temperature usually drops to around
5 °C. However, it dropped to
3 °C in April 1994.

On the warmest days of the month, the temperature usually reaches around
31 °C. However, it reached
35.9 °C in April 2004.

Precipitation amounts to
135 mm, distributed over 5 days.
The day lasts on average 11 hours and 10 minutes.

There are on average 6 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is of
7.5 kph.
May is generally a very mild month. The average temperature is of
15 °C, with a minimum of
9.6 °C and a maximum of
20.3 °C.

On the coldest nights of the month, the temperature usually drops to around
2 °C. However, it dropped to
-0.4 °C in May 1997.

On the warmest days of the month, the temperature usually reaches around
27 °C. However, it reached
30.8 °C in May 1999.

Precipitation amounts to
135 mm, distributed over 6 days.
The day lasts on average 10 hours and 25 minutes.

There are on average 5.5 hours of sunshine per day. So, the sun shines 53% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
6.5 kph.
June is generally a mild month. The average temperature is of
12.7 °C, with a minimum of
7.7 °C and a maximum of
17.7 °C.

On the coldest nights of the month, the temperature usually drops to around
-0.5 °C. However, it dropped to
-6 °C in June 2002.

On the warmest days of the month, the temperature usually reaches around
24.5 °C. However, it reached
28.2 °C in June 2004.

Precipitation amounts to
130 mm, distributed over 6 days.
The day lasts on average 10 hours and 0 minutes. June 21, the winter solstice, is the shortest day of the year in the Southern Hemisphere.

There are on average 4.5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is of
6.7 kph.
July, the coldest month of the year, is generally a mild month. The average temperature is of
11.4 °C, with a minimum of
6 °C and a maximum of
16.9 °C.

On the coldest nights of the month, the temperature usually drops to around
-1.5 °C. However, it dropped to
-3 °C in July 1993.

On the warmest days of the month, the temperature usually reaches around
26 °C. However, it reached
30.2 °C in July 2005.

Precipitation amounts to
120 mm, distributed over 6 days.
The day lasts on average 10 hours and 10 minutes.

There are on average 4.5 hours of sunshine per day. So, the sun shines 46% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
7.2 kph.
August is generally a mild month. The average temperature is of
13.6 °C, with a minimum of
7.8 °C and a maximum of
19.4 °C.

On the coldest nights of the month, the temperature usually drops to around
0 °C. However, it dropped to
-2.4 °C in August 1992.

On the warmest days of the month, the temperature usually reaches around
28.5 °C. However, it reached
34.7 °C in August 2002.

Precipitation amounts to
115 mm, distributed over 7 days.
The day lasts on average 11 hours and 0 minutes.

There are on average 5.5 hours of sunshine per day. So, the sun shines 48% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is of
7.7 kph.
September is generally a very mild month. The average temperature is of
14.8 °C, with a minimum of
9.1 °C and a maximum of
20.5 °C.

On the coldest nights of the month, the temperature usually drops to around
1.5 °C. However, it dropped to
-1 °C in September 2003.

On the warmest days of the month, the temperature usually reaches around
29 °C. However, it reached
37.6 °C in September 1994.

Precipitation amounts to
105 mm, distributed over 7 days.
The day lasts on average 11 hours and 55 minutes.

There are on average 6 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is of
9 kph.
October is generally a very mild month. The average temperature is of
17.9 °C, with a minimum of
12.2 °C and a maximum of
23.5 °C.

On the coldest nights of the month, the temperature usually drops to around
4 °C. However, it dropped to
0.2 °C in October 1999.

On the warmest days of the month, the temperature usually reaches around
31 °C. However, it reached
34.1 °C in October 1993.

Precipitation amounts to
110 mm, distributed over 6 days.
The day lasts on average 13 hours and 0 minutes.

There are on average 7 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is of
9.5 kph.
November is generally a warm month. The average temperature is of
19.8 °C, with a minimum of
13.6 °C and a maximum of
26 °C.

On the coldest nights of the month, the temperature usually drops to around
6 °C. However, it dropped to
2.2 °C in November 2003.

On the warmest days of the month, the temperature usually reaches around
33 °C. However, it reached
35.8 °C in November 1996.

Precipitation amounts to
110 mm, distributed over 6 days.
The day lasts on average 13 hours and 55 minutes.

There are on average 8 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 69%.
The average wind speed is of
9.6 kph.
December is generally a warm to hot month. The average temperature is of
22.7 °C, with a minimum of
16.2 °C and a maximum of
29.1 °C.

On the coldest nights of the month, the temperature usually drops to around
8.5 °C. However, it dropped to
5.2 °C in December 1995.

On the warmest days of the month, the temperature usually reaches around
35 °C. However, it reached
40.7 °C in December 1995.

Precipitation amounts to
110 mm, distributed over 5 days.
The day lasts on average 14 hours and 20 minutes. So the days are long. December 21, the summer solstice, is the longest day of the year in the Southern Hemisphere.

There are on average 8.5 hours of sunshine per day. So, the sun shines 59% of the time.
The average humidity is 66%.
The average wind speed is of
9.1 kph.