diff --git a/esphome/components/atc_mithermometer/atc_mithermometer.cpp b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
index f8bbd9d55e..7b5cdcfa20 100644
--- a/esphome/components/atc_mithermometer/atc_mithermometer.cpp
+++ b/esphome/components/atc_mithermometer/atc_mithermometer.cpp
@@ -65,12 +65,11 @@ optional<ParseResult> ATCMiThermometer::parse_header_(const esp32_ble_tracker::S
     return {};
   }
 
-  static uint8_t last_frame_count = 0;
-  if (last_frame_count == raw[12]) {
-    ESP_LOGVV(TAG, "parse_header(): duplicate data packet received (%hhu).", last_frame_count);
+  if (this->last_frame_count_ == raw[12]) {
+    ESP_LOGVV(TAG, "parse_header(): duplicate data packet received (%hhu).", this->last_frame_count_);
     return {};
   }
-  last_frame_count = raw[12];
+  this->last_frame_count_ = raw[12];
 
   return result;
 }
diff --git a/esphome/components/atc_mithermometer/atc_mithermometer.h b/esphome/components/atc_mithermometer/atc_mithermometer.h
index 3dde5f1868..0f472c11b9 100644
--- a/esphome/components/atc_mithermometer/atc_mithermometer.h
+++ b/esphome/components/atc_mithermometer/atc_mithermometer.h
@@ -38,6 +38,8 @@ class ATCMiThermometer final : public Component, public esp32_ble_tracker::ESPBT
   sensor::Sensor *battery_voltage_{nullptr};
   sensor::Sensor *signal_strength_{nullptr};
 
+  uint8_t last_frame_count_{0};
+
   optional<ParseResult> parse_header_(const esp32_ble_tracker::ServiceData &service_data);
   bool parse_message_(const std::vector<uint8_t> &message, ParseResult &result);
   bool report_results_(const optional<ParseResult> &result, const char *address);