Spain is currently experiencing an intriguing \u00a0climatic phenomenon\u00a0. Without any advance warning or apparent cause, the \u00a0thermometers\u00a0 have shot up, registering temperatures significantly higher than normal for this time of year. As we move into late September 2025, according to AEMET<\/a>, we can expect a resurgence of warmer weather known as the \u201ctemperature rebound.\u201d<\/p>\n This warm spell, colloquially referred to as \u00a0Veranillo de San Miguel\u00a0 or \u00a0Membrillo\u00a0, typically graces the end of September and early October. Named after the festival of \u00a0San Miguel\u00a0 celebrated on September 29, this period surprisingly represents a segment of good weather and elevated temperatures.<\/p>\n But what’s fascinating is that the phenomenon itself is often said to lack a scientific basis. In reality, claims about the Veranillo de San Miguel can be misleading. As we uncover the science behind it, we find that there is a \u00a0clear explanation\u00a0 for why these “summers” have been occurring for the last three decades. For just a couple of days, temperatures rise above their historical averages as September winds down.<\/p>\n In fact, these fluctuations don’t even require substantial increases in temperature. A slight uptick is sufficient to prompt discussions about the \u00a0Veranillo de San Miguel\u00a0, treating it almost as another season.<\/p>\n The phenomenon can often be attributed to a strong \u00a0confirmation bias\u00a0 affecting popular meteorology. As noted in various studies, we have a propensity to \u201cfavor, search, interpret, and remember information that confirms our pre-existing beliefs.\u201d This cognitive bias means that when two or three days of warmer temperatures appear at the end of September, they reinforce the perception of a \u00a0\u201csummer\u201d\u00a0 period, even if the specifics are inconsistent.<\/p>\n Essentially, we observe a regularity in this phenomenon simply due to its high probability. Most years, a warm stretch occurs during this time, aligning with popular sentiment, even when actual temperatures may not consistently reflect traditional summer ranges.<\/p>\n So, will there indeed be a \u201csummer\u201d this year? The answer is a resounding \u00a0yes\u00a0. Just before the anticipated arrival of Hurricane Gabrielle, which is set to make landfall in the west of the Iberian Peninsula, Spain will be graced with a warm and stable weather system. An idyllic setting to wrap up the summer season.<\/p>\n However, what follows is a stark transition. Traditionally, the advent of \u00a0autumn\u00a0 brings with it a sense of \u00a0instability\u00a0. The impending arrival of a hurricane only compounds this notion, emphasizing that summer is concluding, and the days of warmth are fleeting.<\/p>\n A storm brewing on the horizon reinforces the uncertainties typically associated with fall, ultimately marking a significant shift in weather patterns.<\/p>\nWhat is the ‘Summer of San Miguel’?<\/h2>\n
The Controversy of Existence<\/h2>\n
The Science Behind the ‘Summer of San Miguel’<\/h2>\n
What Lies Ahead?<\/h2>\n