Ritu (Indian season)

Ritu (Sanskrit: ऋतु) defines "season" in different ancient Indian calendars used in countries of Pakistan, India, Bangladesh, Nepal and Sri Lanka, and there are six ritus (also transliterated rutu) or seasons. The word is derived from the Vedic Sanskrit word Ṛtú, a fixed or appointed time, especially the proper time for sacrifice (yajna) or ritual in Vedic religion; this in turn comes from the word Ṛta (ऋत), as used in Vedic Sanskrit literally means the "order or course of things". This word is used in nearly all Indian languages.

North, West, and Central Indian calendars, South

Nepal and India observes six ecological seasons.[1][2] Southern parts of India experiences the seasons on a different schedule than the one depicted here.

No.	Ritu	Season	Hindu lunar months	Gregorian month	Characteristics	Seasonal festivals
1	Vasanta वसन्त	Spring	Chaitra and Vaishakha	March & April	Temperature around 20-30 degrees Celsius; vernal equinox occurs in the middle of this season. First spring harvest along with harvest festivals.	Vasant panchami, Ugadi, Gudhi Padwa, Holi, Rama Navami, Vishu/Rongali Bihu/Baisakhi/Brahmin New Year, Hanuman Jayanti
2	Grīṣma ग्रीष्म	Summer/Hot Season	Jyeshtha and Ashadha	~ May & June	Very hot, temperatures up to 45-50 degrees Celsius; summer solstice occurs. This is one of the two typical Indian/ Hindu Marriage Seasons.	Vat Pournima, Rath Yatra, Guru Purnima
3	Varṣā वर्षा	Monsoon/Rainy Season	Shravana (Sawan) and Bhadrapada (Bhado)	~ July & August	Very hot, very humid and heavy monsoon rains; begins with the lunar month AFTER the summer solstice.	Raksha Bandhan, Krishna Janmaashtami, Ganesh Chaturthi, Nuakhai , Onam, Gurujonar Tithi, Mahalaya Amavasya
4	Sharad शरद्	Autumn	Ashwina or Ashvayuja (Kwar, Asauj) and Kartika	~ Late- September, October & mid-November	Mild temperatures; 19-25 degrees Celsius; autumnal equinox occurs in the middle of this season. First autumn harvest occurs along with harvest festivals. Some trees in the Himalayas or upper elevations change colors much like in northern latitudes across the world.	Navaratri, Vijayadashami, Sharad Purnima, Bihu, Deepavali, Dhanatrayodashi, Kartik Purnima
5	Hemanta हेमन्त	Prewinter/Cool Season	Margashirsha (Agrahayana, Agahan) and Pausha (Pus)	~ Late November & December	Very pleasant temperatures; generally, 19-25 degrees Celsius; ends with the winter solstice. Some trees in the Himalayas and other hills complete shedding their leaves much like in northern latitudes across the world.	(mid-Winter celebration) Margashira Mahotsavam. Music Season with a number of Indian Carnatic classical music and dance concerts.
6	Shishira शिशिर	Winter/Dewy Season	Magha and Phalguna	~ January & February	Moderately cold, but pleasant during occasional sunshine; temperatures may decrease below 10 degrees Celsius. This season is typical to tropical and subtropical regions because trees actually shed their leaves in this season in tropical areas; starts with the winter solstice.	Shivaratri, Shigmo, Tamil New Year, Sankranthi

East Indian Calendars

East Indian Hindu (Bengali and Mithila which too starts its new year from Mesh Sankranti, in fact, Nepali and Assamese and Odia Hindus too do the same, the season names are in all other in Sanskrit Vasanta, Grishma, Varsha, Sharada, Hemanta, Shishira) calendar. The Bengali Calendar is similar to the Sanskrit calendar above, but differs in start and end times which moves certain dates/days around (i.e., Vasant Panchami occurs here in Vasant ritu but in the calendar above, it occurs in Shishir as that is the Magha Shukla Panchami). The East Indian Calendar has the following seasons or ritus:

Bengali season	Start	End	Bengali months	ladhaki	English
Grishmo (গ্রীষ্মকাল)	Mid-April	Mid-June	Boishakh, Joishtho	sos ka, སོས་ག	Summer
Borsha (বর্ষাকাল)	Mid-June	Mid-August	Asharh, Srabon	yarka, དབྱར་ཁ	Monsoon
Shorot (শরৎকাল)	Mid-August	Mid-October	Bhadro, Ashwin	stonka, སྟོན་ཀ	Early Autumn
Hemonto (হেমন্তকাল)	mid-October	mid-December	Kartik, Ogrohayon	dgun stod, དགུན་སྟོད།	Late Autumn
Shit (শীতকাল)	mid-December	mid-February	Paush, Magh	dgun smid, དགུན་སྨད	Winter
Bosonto (বসন্তকাল)	mid-February	mid-April	Phalgun, Choitro	shid ka, དཔྱིད་ཀ	Spring

South Indian Calendars

Malayalam calendar

The Malayalam calendar or Kollam Era, a solar and sidereal Hindu calendar used in Kerala, follows a pattern of six seasons slightly different from North Indian Calendars.

No.	Ritu	Season	Malayalam solar months	Sanskrit solar months	Gregorian months	Seasonal festivals
1	Vasantam വസന്തം	Spring	Makaram (second half)-Kumbham-Meenam (first half)	Makara (second half)-Kumbha-Mīna (first half)	February & March	Vasantha Panchami, Holi
2	Grishmam ഗ്രീഷ്മം	Summer	Meenam (second half)-Medam-Idavam (first half)	Mīna (second half)-Meṣa-Vṛṣabha (first half)	April & May	Vishu
3	Varsham വർഷം	Monsoon or Rain	Idavam (second half)-Mithunam-Karkatakam (first half)	Vṛṣabha (second half)-Mithuna-Karkaṭaka (first half)	June & July	Karkataka Vavu (marks the beginning of Sharad season)
4	Sarath ശരത്ത്	Early Autumn	Karkitakam (second half)-Chingam-Kanni (first half)	Karkaṭaka (second half)-Siṃha-Kanyā (first half)	August & September	Rakshabandhanam, Krishna Janmashtami (Sri Krishna Jayanti), Onam
5	Hemantham ഹേമന്തം	Late Autumn	Kanni (second half)-Thulam-Vrischikam (first half)	Kanyā (second half)-Tulā-Vṛścik‌‌‌am (first half)	October & November
6	Sisiram ശിശിരം	Winter	Vrischikam (second half)-Dhanu-Makaram (first half)	Vṛścik‌‌‌am (second half)-Dhanu-Makara (first half)	December & January

Tamil calendar

The Tamil Calendar follows a similar pattern of six seasons as described for north Indian Hindu calendars which in fact need adjustment as taking new year from Grishma like that Bengali calendar....

Tamil season Names	English Meaning	Gregorian Months	Tamil Months
Muthuvenil (Summer) முதுவேனில்	Matured heat / warmth	April 15 to June 14	Chithirai and Vaikasi
Kar (Monsoon) கார்	Dark Clouds	June 15 to August 14	Ani and Adi
Kulir (Autumn) குளிர்	Cold / Chill	August 15 to October 14	Avani and Purattasi
Munpani (Winter) முன்பனி	Early (Frontal) Dew / Mist	October 15 to December 14	Aipasi and Karthikai
Pinpani (Prevernal / Early Spring) பின்பனி	Late (Rear) Dew / Mist	December 15 to February 14	Margazhi and Thai
Ilavenil (Spring) இளவேனில்	Tender heat / warmth	February 15 to April 14	Masi and Panguni

In culture

The seasons are described in literature such as the Sanskrit poem Ṛtusaṃhāra written by the legendary Sanskrit poet Kālidāsa.

Names of the ritu are commonly used for persons: typically, Vasant, Sharad, Hemant, Shishir and Varsh are "male" names; "female" names include Vasanti, Sharada, Hemanti, Grishma and Varsha.