Climate
April and May sees a significant increase in temperature.  Seoul’s average monthly temperature increases by six degrees to 17°C.  Daytime averages climb to 22°C.  Nights see a significant warming from the previous month, averaging 11°C. 
Electricity
The standard voltage in Korea is 220 volts at 60 Hertz, and the outlet has two round holes. If you do not have a multi-voltage travel adapter, you may ask to borrow or purchase one from your hotel's front desk. You can also find them at the airport, retail stores, major duty-free shops, and even convenience stores.
SIM Card Purchase (Korea SIM Card)
Travelers can purchase a SIM card to insert in their personal cell phone device to enjoy unlimited data or receive a personal number while traveling in Korea. These prepaid SIM cards usually cost less than roaming services and offer unlimited data for a period of 5, 10 or 30 days. The SIM cards can be purchased at CU and 7-Eleven convenience stores at Incheon International Airport and Korea SIM Card’s official website. Although they can also be found at certain CU and 7-Eleven branch stores in Seoul and Busan, visitors are recommended to make a purchase in advance via online or at the airport.
*Korea SIM Card website: www.krsim.net (English, Chinese)
Banks / ATM (Automated Teller Machines)
Banks are open Monday through Friday from 9am to 4pm. ATM service is typically available until 10pm, although some ATMs offer service after 10pm with additional fees.
Credit Cards
Most of the businesses in Korea widely use and accept payment by credit cards, including at major hotels, department stores, and general shops. Visa, MasterCard, American Express and other credit cards can be used; however check the service availability before making purchases as some stores may not provide this service.
Currency Exchange and Taxes
• Currency : Korea's official monetary unit is the won(₩).

• Tax : Value-Added Tax (VAT) is levied on most goods and services at a standard rate of 10% and is included in the retail price. In tourist hotels, this 10% tax applies to rooms, meals and other services and is included in the bill.
Phone Calls to Seoul
The country code for Korea is +82 and the area code for Seoul is 2. For example, to call 1234-5678 or 010-1234-5678 from the US, one must dial: 011 (US exit code)-82-21234-5678 or 011(US exit code)-82-10-1234-5678.
Time Differences
Korea’s standard time zone is GMT +9 hours.
Wi-Fi
As a leading nation in information technology, Korea provides one of the best internet connections worldwide. Take privilege of the world’s fastest internet speed through Wi-Fi for your convenience during your time in Korea.
Tipping
Tipping is not customary in Korea. Sometimes, expensive restaurants and luxury hotels may add a service charge of 10%. Thus, you do not necessarily have to prepare for extra charges since it will be included in the bill.
Emergency Numbers
Dial 119 for the fire department and medical assistance, and 112 for the police. A hotel staff or hotel manager can arrange for a doctor or an ambulance in an emergency (though most Korean operators speak little or no English).
Useful Websites
Information about Seoul: http://english.seoul.go.kr
Information about Korea: http://www.tour2korea.com
Incheon Int’l Airport: http://www.cyberairport.kr
Korean Ministry of Foreign Affairs and Trade: http://www.mofa.go.kr/eng/index.do