Warm Spell : A period of abnormally warm weather. Heat waves and warm spells have various and in some cases overlapping definitions. See also Heat wave
C.B., V. Barros, T.F. Stocker, D. Qin, D.J. Dokken, K.L. Ebi, M.D. Mastrandrea, K.J. Mach, G.-K. Plattner, S.K. Allen, M. Tignor, and P.M. Midgley (Eds.), Annex II, Acronyms and Glossary of Terms (In Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation), Intergovernmental Panel on Climate Change (IPCC), IPCC Secretariat, World Meteorological Organization, Geneva, Switzerland 2012. https://www.ipcc.ch/pdf/special-reports/srex/SREX- Annex_Glossary.pdf, (ND Emr/ Extrm Heat - Amer) {969}