The timing of flowering is a crucial developmental phase of plants that is tightly controlled by seasonal cues, including photoperiod and temperature. The rising global temperature due to climate change accelerates the flowering time of most plants and greatly impacts our agriculture. The timing of flowering is controlled by a mobile protein called florigen, which is encoded by the FLOWERING LOCUS T (FT) gene in Arabidopsis. FT is expressed in leaf phloem companion cells, and the protein undergoes long-distance transport to the shoot apical meristem to initiate flowering. FT belongs to the conserved phosphatidylethanolamine binding protein family. Here, we show that FT is interacts with negatively charged phospholipids, specifically phosphatidylglycerol (PG), and this interaction sequesters FT in the cellular membranes. Low ambient temperatures facilitate FT sequestration in the cellular membrane of companion cells, reducing soluble FT levels for long-distance transport and thus delaying flowering. Additionally, we also observed the interaction of FT with THYLAKOID FORMATION 1 (THF1), which is chloroplast localized integral protein. The coiled-coil domain of THF1 interacts with the anion binding pocket of FT to sequester FT in the outer chloroplast envelope, especially at low ambient temperatures. The double mutant of PHOSPHATIDYLGLYCEROLPHOSPHATE SYNTHASE 1 (pgp1) and thf1 results in complete temperature insensitivity, suggesting a crucial role of florigen sequestration by membrane lipids and proteins in plant temperature sensing.