diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -521,6 +521,9 @@
         connect(_clientModel, SIGNAL(networkActiveChanged(bool)), this,
                 SLOT(setNetworkActive(bool)));
 
+        modalOverlay->setKnownBestHeight(
+            _clientModel->getHeaderTipHeight(),
+            QDateTime::fromTime_t(_clientModel->getHeaderTipTime()));
         setNumBlocks(_clientModel->getNumBlocks(),
                      _clientModel->getLastBlockDate(),
                      _clientModel->getVerificationProgress(nullptr), false);
@@ -555,10 +558,6 @@
             // value in the model.
             setTrayIconVisible(optionsModel->getHideTrayIcon());
         }
-
-        modalOverlay->setKnownBestHeight(
-            clientModel->getHeaderTipHeight(),
-            QDateTime::fromTime_t(clientModel->getHeaderTipTime()));
     } else {
         // Disable possibility to show main window via action
         toggleHideAction->setEnabled(false);
diff --git a/src/qt/clientmodel.h b/src/qt/clientmodel.h
--- a/src/qt/clientmodel.h
+++ b/src/qt/clientmodel.h
@@ -8,6 +8,8 @@
 #include <QDateTime>
 #include <QObject>
 
+#include <atomic>
+
 class AddressTableModel;
 class BanTableModel;
 class OptionsModel;
@@ -80,6 +82,10 @@
     QString formatClientStartupTime() const;
     QString dataDir() const;
 
+    // caches for the best header
+    mutable std::atomic<int> cachedBestHeaderHeight;
+    mutable std::atomic<int64_t> cachedBestHeaderTime;
+
 private:
     OptionsModel *optionsModel;
     PeerTableModel *peerTableModel;
diff --git a/src/qt/clientmodel.cpp b/src/qt/clientmodel.cpp
--- a/src/qt/clientmodel.cpp
+++ b/src/qt/clientmodel.cpp
@@ -33,6 +33,8 @@
 ClientModel::ClientModel(OptionsModel *_optionsModel, QObject *parent)
     : QObject(parent), optionsModel(_optionsModel), peerTableModel(0),
       banTableModel(0), pollTimer(0) {
+    cachedBestHeaderHeight = -1;
+    cachedBestHeaderTime = -1;
     peerTableModel = new PeerTableModel(this);
     banTableModel = new BanTableModel(this);
     pollTimer = new QTimer(this);
@@ -66,15 +68,27 @@
 }
 
 int ClientModel::getHeaderTipHeight() const {
-    LOCK(cs_main);
-    if (!pindexBestHeader) return 0;
-    return pindexBestHeader->nHeight;
+    if (cachedBestHeaderHeight == -1) {
+        // make sure we initially populate the cache via a cs_main lock
+        // otherwise we need to wait for a tip update
+        LOCK(cs_main);
+        if (pindexBestHeader) {
+            cachedBestHeaderHeight = pindexBestHeader->nHeight;
+            cachedBestHeaderTime = pindexBestHeader->GetBlockTime();
+        }
+    }
+    return cachedBestHeaderHeight;
 }
 
 int64_t ClientModel::getHeaderTipTime() const {
-    LOCK(cs_main);
-    if (!pindexBestHeader) return 0;
-    return pindexBestHeader->GetBlockTime();
+    if (cachedBestHeaderTime == -1) {
+        LOCK(cs_main);
+        if (pindexBestHeader) {
+            cachedBestHeaderHeight = pindexBestHeader->nHeight;
+            cachedBestHeaderTime = pindexBestHeader->GetBlockTime();
+        }
+    }
+    return cachedBestHeaderTime;
 }
 
 quint64 ClientModel::getTotalBytesRecv() const {
@@ -248,6 +262,11 @@
                                            ? nLastHeaderTipUpdateNotification
                                            : nLastBlockTipUpdateNotification;
 
+    if (fHeader) {
+        // cache best headers time and height to reduce future cs_main locks
+        clientmodel->cachedBestHeaderHeight = pIndex->nHeight;
+        clientmodel->cachedBestHeaderTime = pIndex->GetBlockTime();
+    }
     // if we are in-sync, update the UI regardless of last update time
     if (!initialSync || now - nLastUpdateNotification > MODEL_UPDATE_DELAY) {
         // pass a async signal to the UI thread