Some May Celebrations in the Philippines

 Some popular festivals celebrated during the month of May in the Philippines.

1. Pattaraday Festival - May 1–5 Santiago City, Isabela - It is celebrated during the foundation day of the City of Santiago in Isabela and the word Pattaraday means Unity in Ybanag language.
2. Panagat Festival - May 2–8 Buruanga, Aklan - It is celebrated as a Thanksgiving to St. Nuestra de Lourdes for a very abundant fishing harvest, hence, it is also known as Fishing Festival in the town of Buruanga, Aklan.
3. Binatbatan Festival of the Arts - First week of May, Vigan - It is a long week celebration started in 1993 by the Save Vigan Ancestral Homes Association, Inc. (SVAHAI) for promoting cultural awarenes in Vigan City, Ilocos Sur.
4. Obando Fertility Rites - May 17, 18 & 19 Obando, Bulacan - It is a very well-known festival in the town of Obando in Bulacan especially for childless couples hoping and praying while dancing in order to please the Virgin of Salambao, San Pascual de Bailon and Sta. Clara.
5. Domorokdok Festival - May 4 Botolan, Zambales - It coincides with the feast of Sta. Monica and the term Domorokdok is a Zambal word the means dance and the dance originated from Barangay San Miguel and the festival promotes unity and cooperation among Botolan residents.
6. Bariw Festival - May 14–15 Nabas, Aklan - It is celebrated to commemorate the patron saint of the town of Nabas in Aklan, St. Isidore the Farmer.
7. Pahiyas Festival - May 15, Lucban, Quezon - Its official longer name is Lucban San Isidro Pahiyas Festival and is also an annual celebration for the patron saint of farmers, San Isidro, and it highlights the town's usage of "kiping" to decorate the houses in Lucban, Quezon.
8. Agawan Festival - May 15, Sariaya, Quezon - It is another commemorative festival to San Isidro De Labrador for the bountiful harvests the townspeople in Sariaya, Quezon experience.
9. Araquio Festival - First Week of May, Gen.Tinio, Nueva Ecija - It is an annual celebration in the town of Gen Tinio in Nueva Ecija that has a re-enactment of the finding of the Holy Cross of Jesus Christ by St. Helena and her son, the Emperor Constantine.
10. Mardigra (Mardi Gras) Festival - May 30, Lucena City, Quezon - It was first celebrated in 1987 which usually starts in May 27 and ends in May 30 to honor the patron saint, St. Ferdinand, and is almost similar to Mardi Gras in Brazil.
11. Samahang Bulaklakan Festival - Last Sunday of May, Siniloan, Laguna - It started in 1914 in the town of Siniloan in Laguna to honor the Virgin Mary of Flowers or Nuestra Senora De Las Flores. 
12. Tapusan Float Parade Festival - May 31, Alitagtag, Batangas - It is celebrated in the town of Alitagtag in Batangas in honor of the Holy Cross and it also incorporates "Santacruzan".

References:

Festivals in the Philippines
PATTARADAY FESTIVAL - ARAW NG SANTIAGO
Panagat Festival Festivals and Fairs
Viva Vigan Festival of the Arts
Obando Fertility Dance (Obando, Bulacan)
Domorokdok Festival in Botolan
Municipality of Nabas Bariw Festival! 
Pahiyas Festival
Agawan Festival in Sariaya
Araquio Festival
'Mardi Gras' in Lucena  
About Samahang Bulaklakan
May 31 – Feast of “Tapusan”